I had similar issues with my oldest. What helped for us was wees on the grass as he was really keen on that and a little reward like a choc bit. Stars or other stickers didn't work and I tried a few times to get him interested on those.
Have you tried a potty at all? My second son didn't want to do the toilet but went on the potty. Maybe because it was his alone IYKWIM.
The little mites can act totally different at daycare. It's almost like they come home and get all cunning and do the opposite of what you want just becasue they know you have no control over how they go to the toilet
