I'm having similar issue with my 3yo boy. He doesn't communicate or give any signs he needs the toilet. My nursey suggested pants then a nappy so he can feel the discomfort but not necessarily make an accident. Maybe try that for the family members and nursey? Anyway good luck mama, I feel your pain
Honestly, my sons been completely toilet trained outside of nursery for 8 months but it took 6months for him to be consistently accident free at nursery. He’s quite shy and reserved. I would get family on board and stick to the same routine outside of nursery, no nappies apart from when he’s asleep. Tell nursery everything you’re doing and they should follow suit. He’ll pick it up in time, if he’s going well outside of school I’d keep going with it. It felt like such a battle but he got there in the end. Pack tonnes of pants and bottoms, socks and spare shoes and keep at it if it’s manageable for everyone
He sounds a lot like my little boy. We managed to crack it over Christmas and here are some things we did. We said we had no more nappies and had to just wear pants/trousers. There wasn’t the option to go back. Like your little boy he did a few accidents in them, didn’t like the feeling and the started to get it. The most annoying would be when he would sit down on the potty, not do anything, and then have an accident literally 30 seconds later. But they didn’t last too long before he got used to it. He didn’t really like sitting on a potty but has loved the potty that looks more like a small toilet. Still now when he is not having accidents, he won’t use a normal potty but will use the little toilet or a bit toilet with an adapter. We gave him stickers for whenever he sat on the potty, and a sticker and a chocolate button when he actually managed to go on the potty.
We didn’t go back to nappies once they were off. He has pull ups on at night and we call them his ‘night time pants’. We haven’t had any leaks in them and it stops the confusion from going from pants to nappies. We got one of the step/seat adapters for the big toilet. When they arrived we built them together and he was SO excited to use them. He actually doesn’t want to use them now but honestly think it was a turning point from not wanting to go to being excited to go.
Awww bless him it sounds like he is doing really well as he's just starting out. They do recommend trying to keep them at home for 3 or 4 days so they can get used to asking for the potty in their own environment, I bet it's the change of environments going to family/nursery. They're distracted at nursery too so always expect accidents when first starting out x