Screen flickering when lifting lid and waking from sleep on Macbook Pro 15?

Question

Iron

I have such a problem, when the macbook is turned off and turned on, it starts up and everything is fine, nothing flickers.
But if it is turned on, close the lid, it goes into sleep mode, and when you open the lid after 10 seconds, it wakes up from sleep mode, the screen starts flickering for about 40 seconds, and after that everything gradually stops, and so on every time you open the lid.
A second-hand Macbook, so I don’t know its history, and one more detail, the keyboard has uneven backlighting, can it be that the keyboard was flooded and this caused such consequences with flickering?