Long story here but will try to simplify.  

My son is 23 and lives with me and his younger sister, 13.  He was diagnosed with bipolar a few years ago.  He also has severe OCD.  

He's had a few severe manic episodes and each time, it seems he goes backwards in ways that are hard to explain.  He sometimes has a hard time connecting and retaining info and is slow to learn new tasks at times but gets it after a few tries. He's a really bright guy at times but sometimes gets confused.  One docs believes he might be slightly autistic but we just don't know for sure what's happening.  He's always had some mystery issue happening since childhood that we could never pinpoint but you'd really never know it on the surface if you met him.  He's capable of being very independent and self-sufficient but makes poor decisions at times that are sometimes hard to explain.   
 He has a complicated situation.  He has a psychiatrist and an OCD therapist and his bipolar is very stable right now.  

Up until he turned 23, he was with an organization that supports young people in his situation...especially with job-related issues.  But the moment he turned 23, he was dropped without warning.  We had forgotten that they only help those up to age 22.  But that's another story.  So he was left with zero support. 

After not working for awhile due to some setbacks, he got a job at a movie theater but never shared any of this struggles with his boss.  They trained him to work concessions, clean the theater, and scan tickets.  He did fine with everything but concessions, where they told him he was "freezing up" too much and they didn't have time to train him.  He said they only gave him one chance to work it and he knew he's get it if they had just let him experience it a bit longer.  He's a good, reliable, excellent worker once he's rolling...but they treat him poorly.  He works four days a week and he says he's always stuck in the front alone for hours scanning tickets and implementing mask rules, which is stressful because he sometimes gets push-back.  Plus it's boring at times and all the social fun and action is happening at concessions but they never allow him to try it.  He says he feels like they "think he's stupid" and he wants to quit now but he needs the  money.  His OCD also makes it challenging at times when he cleans the theater and so he's sometimes slower with that than they would like and they get frustrated with him.  

But here's the part that makes it all the more complicated:  On the flip side of all this, I think sometimes they'll tell him something and he doesn't hear the info correctly.  For example, he called in sick recently and he claimed they told him that if he stayed home, he couldn't come in for ten days due to covid precaution rules.  But if he did come in and push through his illness, that they would not make him stay home ten days and just let him work.  This logic made no sense to me and I suspect my son heard it all wrong, which has happened before.  Sure enough, he showed up to work today still not feeling well and found out they had marked him as not coming in although he claimed to me they told him to come in anyway.  His info is always a bit convoluted. and I suspect he heard it all wrong from the get-go.  

Another example is he ordered a lyft recently to meet his buddy and they took him to the wrong address but he didn't realize it till he arrived because he has poor sense of direction and didn't connect the longer mileage and logically figure it out. 

So, it's all these unexpected challenges that pop up and the people around him don't realize his struggles.   So, he's now on the verge of wanting to quit and needs his boss to understand that he has some challenges, so I feel I have to reach out to her now.  I want to be his advocate but he is 23 so clearly not a little kid needing his mom to rescue him.  But I'm not sure what to do.  I also don't know how much info to share about his mental health issues to her.  What do I say??  The organization he was with would have helped with this kind of thing but we have no one now.  Even his OCD therapist and psychiatrist have offered no guidance with any of this and say we need support they cannot offer.  

We are in the Portland, Oregon area, by the way.  Does anyone have any suggestions??  I hope all this makes sense.