Does he talk about nursery and whether he likes it there? Unless there are significant barriers to it, I would move him to a new setting. If only, to get a second opinion before he starts school.
My son was super happy at his nursery until he moved to the pre-school room. It was very busy, noisy, with older children and he'd lost his friends who were younger so still in the toddlers room. The staff organised a lot of group activities to channel the kids, like crafts, group songs, story times, maths, writing etc... multiple times a day, that my son hated. I think there was a lot of pressure on him to join the group activities .
It took a few months for us to understand what was wrong. We moved him to a pre-school that was a much bigger setting with more children , but much more space inside and outside.
They had 2x10 min group times + lunch and tidying up, but that's was it. Kids were free to do whatever they liked the rest of the day, free flow indoor and outdoor, no pressure to join anything at all.
He didn't start joining in the seated group stuff until he was 4.5. The only thing he liked was story time, but he didn't join the singing or craft or drawing until the end of the year. Didn't join the birthday parties either.
But he made great friends and spent most of his day running outside, and building countless trains and houses and universe with blocks and toys in his own.
His key worker was great, and if he hadn't joined the phonics group session for instance, she would find 10 min during the day to catch up with him 1-1 or with a friend.
He's now at school, and according to his teachers he's a great team player, joins in everything, made multiple friendships already, no behaviour problems at all.