Flappy Bird with neural network not working properly

I'm trying to make a game like Flappy Bird but with a neural network. Here is the link to the project: https://github.com/Nikolay-Egoshin/Bouncy-Bird-NN. Everything can be said to work, except for the most important thing - the birds do not learn normally. They fly through the first pipe at most, but on the next attempts they can no longer do it. Help me find the problem please.