Hello everyone! We've started some serious problems with sleep. We us…

Hello everyone! We've started some serious problems with sleep. We used to put the baby in his crib and he would fall asleep on his own, without crying. Now during daytime naps there are tantrums, even though I control wake time and put him in the crib as soon as the first signs of tiredness appear. How can I avoid mistakes and not create incorrect associations with sleep? Do your babies also behave like this at three months old? ?