hello, (scuse for my english ...)

At the same time, the golden child and another child are born : my max population is 66 !!!
but now, I stop to 65.

In version 1.1, the Golden Child will be born even when your village population is at the limit (65 villagers on most devices). That one birth is the exception to the population limit, and you will not be able to exceed it at any other time.

The Max Population listed on the Statistics Screen is the highest population achieved in your village at any point in your game, not your population limit.

I've been playing for 252 hours, and had 65 villagers quite a while ago, along with the GC. After this occurred, the population dropped down to 63, but now it's up to 66. How can that be?