Welcome @Catssitonhats - yes, it is refreshing to be able to talk about the challenges without the response being 'LTB' every time when that's not what you're even asking about.
DH has signed contract for this one. I really hope it works out, especially as it's going more back to what he did before project management, which was the thing where jobs never worked out in the long term, he always got hit with criticisms that were kind of personal and vague and not criteria he could just meet, that I think are to do with the ADHD/autism.
Our oldest (nearly 17) has just been to GP about autism assessment as well. Interestingly @SpecialMangeTout3 , they are also looking into whether they might have ME/CFS. Blood tests just come back normal, they have been complaining of mind fog and unrefreshing sleep that they think date from after them getting shingles (!) 18 months ago. I wonder if it could be a long post-viral thing rather than ME/CFS per se, though the line between those two things is vague. My sister also had post viral illness around same age that hung around for about a year, but she got over it. My mum has had pretty bad ME for 30 years now, so I know fairly well what it can look like, but obviously it can vary a lot from person to person. I worry, if it is CFS, whether DC is heading for a terrible collapse like my mum did after a period of unexplained symptoms. That said, DC got through a solid year of revision for GCSEs last year and came out with outstanding results, so if there was any time for them to totally collapse it would have been during or just after that period.
I also wonder, if they are autistic, whether it could be related to that and tiredness from a certain amount of masking and just doing a LOT of stuff.