Yes! The holidays of 2018 were Hell- I'd paid a fortune for him to sit in his room and stare at his phone, coming out to whinge that the WiFI was crap (it wasn't). Never went out, in a bit of low-level bother at school (forgetting homework, grunting at people), wanted to give up his sport.
I talked him into staying with the sport, ignored the rest. Helped to get him back on top of homework. Decided to ride it out.
He's now 16, fortunately he decided to listen last September when we warned him that he needed to work at school in case he didn't take exams. He got decent grades and is now doing A Levels in subjects he genuinely loves.
He's become far more sociable, his girlfriend comes over often and he likes knowing that she is always welcome. He went on a walking holiday with friends over the summer just before the GCSE results came out. He has now retired from his sport as he wants to focus on his studies.
He's far from perfect- that state of his room is fairly awful, he needs a gentle nag to take the bins out- but it's all pretty good. He just needed time to grow up. I think a lot of his friends were the same. Oh, he still doesn't really know what he wants to do. I've decided that things have been so muddled for him over the last 2 years that he should just focus on school and uni, we'll think about the later steps in a year or so.