I think it's the old adage "a change is as good as a rest".
The change may help. I keep my toddler bedroom door pulled to, so I can sneak in and check without waking her.
I posted something on another thread the other day with similar problems. And this worked for them. Maybe luck?
My daughter was like a Jack in the Box in the bed when I first moved her into it and kept laughing and opening the door and coming out, I explained she was going to be a big girl like Peppa Pig and sleep in a bed on the first night.
Over a number of nights I repeatedly lay her back down without talking to her, or looking at her and left again, multiple times. Eventually the game got boring as I never reacted and she stopped doing it. I had to child proof the room and remove all the toys, so she wouldn't play with them instead, if being put to bed in the early days. Some children do end up needing a stair gate on their door as they get older if problematic. Fingers crossed yours will be an angel
Her daytime naps were interesting once in a bed in the early days, I had to repeat the old exercise of repeatedly laying down. If you make sure they're tired before laying down (sorry stating the obvious) that's your best bet for daytime naps.
I do think once a toddler learns that they can say no or resist certain things, it's a whole new ball game . My daughter regularly suddenly decides she doesn't like something that previously she had done a million times and had no problems with. But this is a whole can of worms, so I won't open it. But it maybe worth trying a bed if you can face it?
Of course there maybe another logical explanation on this sudden change that I cannot think of. Perhaps another mumsnetter will be along soon with a plan.
Best of luck x