Room change, potty training regression

[Applesandpears58]

We’ve been potty training around 3 months, on the whole it’s been pretty good. DS has just moved from toddler to pre school room at nursery, and seems to be having a lot more accidents. They’ve asked whether they should be putting him in nappies when he’s run out of clean clothes, which I’m against, as I feel this is a step back, but what choice do we have.
When he’s at home, he’s great, when he needs the toilet, he takes himself off and does his business.
in the toddler room they asked him a lot more directly whether he needs to go, now I think it’s a more general, ‘does anyone need the toilet?’ I understand why, as they need to learn to ask and it’s preparing them for school, but AIBU to expect in the transition period between rooms, they should be asking him directly a bit more.
Has anyone else had this? How long did it last (assuming it improves), and any advice?

He's not been out of nappies that long. If the issue is what to do when they run out of clean clothes, send more clean clothes. And say to tell him it's time for a wee now rather than a generic ask.

They should not be putting him in nappies. It will confuse him and add to regression. Do they not have any spares? Send in loads and loads of spares so he doesn't end up in nappies. Buy a pack of pants just for nursery and send extra trousers. Ask nursery to have some sort of timer system say for every 20-40 minutes and tell your ds it's time to go for a wee. This should be basic for them. Your poor DS. I'm not surprised if he is regressing if they are putting him back in nappies 😢
I know there's a preparation for school aspect but he's so young still. There's so much time.
Hope things improve. Speak to the manager if needs be xx