Incidents with my Minecraft for Windows 10 with 1.16

Hello, my name is Nelson Herrera I have incidents with Minecraft for Windows 10 and there are two incidents, I would appreciate it if you could tell me if there is a possible solution to my problem and I will tell you in the following:

1.-When I play an old world at version 1.16 my keyboard takes time to respond with the game, there are times when I walk or run and after a while the character walks alone through the lag of the game and I am playing alone in solitary mode.
2.-When I go to the new areas of the nether the game begins to close unexpectedly and I do not know why it happens I only enter the nether for a few minutes and out of the blue the game closes automatically, I do not know if there could be a possible solution.

I thank you in advance for your attention and understanding when reading this message.
And I hope I can receive a response and thank you.