I don't think you can judge anything from this year if he's doing remote learning.  So many kids are failing, falling behind and not doing the work with remote schooling.  It takes a certain kind of kid to deal well with remote learning - online learning takes self-motivation, which is something a lot of young kids just don't have.  Thank goodness the public school my skids go to has been in-person all year, because remote learning appears to have been a disaster.  It certainly was for them last spring.

Are BM and your DH imposing consequences on SS for his failure to do his work?  A lot of teens have an instant gratification mindset, and they're going to do what they want if someone isn't incentivizing/forcing them to do otherwise.  And what they want isn't to do school work.  

What is SS interested in and what does he want to do?  My cousin has ADHD and was a pretty terrible student.  His parents literally had to sit with him from first grade on and make sure his work got done each night (and this wasn't during online learning).  His big interest was cars and motorbikes, and he wanted to be a mechanic.  He needed to pass his first couple years of high school to get into the vo-tech mechanic program at the high school, and that was his motivation.  It still took a lot of nagging and oversight on the part of my aunt and uncle to make sure he did and turned in his work, but once he was in the vo-tech program he excelled, got additional education and training after high school, and he's a very successful diesel mechanic today.  It wasn't the path that most kids at his high school took, but it was the one that worked for him.  But getting into the mechanic program was the carrot that was used to get him through freshman and sophomore years.

my son now 19, really struggled through the early years of high school , he was diagnosed with central auditory processing disorder and dyslexia , so he struggled extremely with heavily worded documents and was on an IEP from the very beginning.   I was really worried about him dropping out as year 9 & 10 were incredibly hard for him and he would start playing up becasue he didnt understand anything being taught.  I had a tutor twice a week which helped him complete his assignments to scrape him through year 10,,,just scrape through!   In year 11 , the private school he went to have a trade college which is fanatastic for kids who arent academic and he could try several different trades like plumbing , electrition, engineering, carpentry and even a chef trade.  Well he finally found something that he could do and loved learning about , he fell in love with engineering fabrication and by the time he completed year 12 , he graduated with highest academic award for engineering in the school, landed an engineering apprenticeship out of 163 applicants.    I think your SS sounds very lazy but also may struggle a lot therefor makes his ADHD 1000 times worse and sometimes they just give up completely before they have even started.  DH and BM need to constantly ride this kid ,, its going to take a huge amount of effort from their part with this kid , but it can be turned around 

I agree not to judge based on his performance during COVID, since probably 50% of kids are doing poorly with remote learning.

That being said, I knew when my SS was 13 that he'd barely graduate and be a Failure to Launch poster boy, and I was right. He's now 21, barely graduated, dropped out of community college after 1 year and hasn't done anything at all for the last 2 years. BUT, in our case, BM did nothing to help him be successful, and DH tried, but SS lived with her and didn't talk to DH for over 3 years.

Going through a lot of this now with YSS. He has always been problematic with doing homework and school. Since BM left him with us and we got him into therapy, we're finding out he has a TON of school-based anxiety that has folded into his laziness. Basically, he falls behind in his school work and starts failing, then his anxiety kicks in about failing and he freezes, and then it just spirals.

What we are finding that works is:

- "Family Homework Nights" where DH and YSS sit in the living room, review his homework list, then tackle the assignments he has due. DH doesn't do it for him, but makes him sit in the living room in front of him to do it. YSS gets it done faster. 

- Making YSS CC his dad on emails to teachers when he turns in assignments late. With COVID and teaching via modules, the teachers have set dates when things are due, but most accept late work to a certain point. At first, I thought YSS was being lazy, but his school work is spread across multiple platforms and you can't check all of them to make sure things submitted correctly. So emailing is the checks-and-balances piece. 

- We're letting YSS fail one class that he knows he'll have to retake over the summer. Granted, YSS is dealing with a lot of crap right now, so this may not be feasible for every kid. BUT, just having permission to fail has actually made him keep up with his work in that class. He's still failing due to falling behind early in the semester, but he is doing so much better at not missing assignments in that class.

- Therapy. Just therapy. YSS has school-based anxiety, and that's what he works through in therapy (among other things). 

- We don't punish YSS for telling us why he didn't do something, only for lying or having "I don't know" as an answer. We'd rather he tell us he hated the assignment, was being lazy, forgot about it, didn't want to do it, etc than give us some BS excuse. Knowing he hates an assignment means DH or I can work with him through it and reassure him that it's okay to hate it. Not knowing the actual cause makes it impossible to try and fix.

BM tried to punish YSS out of this pattern, and it only fed into his anxiety. What he needed, even if he couldn't verbalize it, was help in getting organized and having someone keep him on task. Should we have to do it for a high schooler? No. But, he's passing all his classes except one and has only 3-5 assignments he's ever behind on before we check in, versus 20-50 last semester (and that's not an exaggeration). The goal is to get him self-sufficient for his sophomore year so we just have to check in with him weekly on his assignment to make sure he's keeping up. It has been night and day difference with DH and I doing a lot of this hand-holding,, and he has really started to keep up with things on his own. I'm really very proud of him for the improvement.

2nd grade teacher here! My SD10 is also one of those students that struggles to barely pass. The pandemic has definitely magnified it and made it more obvious, but honestly she has been having trouble since Kindergarten. She has a special IEP and 504 plan. She has also been diagnosed with ADHD. BM FINALLY agreed to try to get her on medication this year. We know it won't be a magic fix, but hoping it will atleast help before she gets to middle school. 

I agree with the above posters that so much of schooling falls back on the parents. Are they following up and holding SK accountable? I know DH just "takes her word for it" and then at the end of the quarter realizes she has a million missing assignments. Same for BM. Neither of them really follow up, blame the pandemic for their crappy parenting and act shocked when they see how poorly she is doing. 

SD also is not motivated, doesn't try, doesn't ask for help from her teachers, the list goes on. There is ZERO effort on the child's part. Also, I personally feel BM has instilled a LOT of this in her. 

BM was extremely bitter when we started dating. Since I was a teacher, and she was PASing, she TOLD SD "you don't have to listen to teachers", "they aren't smart because they don't get paid a lot", "your school is stuck up and the principal doesn't like mommy"... BM caused SD to have a bad attitude about education from the start IMHO. It's hard to undo the damage she caused. I realized it's not my responsibilty.

The only goal at this point is to try to get her "ready to launch" when it's her time. Whether it be a GED, some kind of trade, etc.