Cant connect on ps4 version on ps5

Hello, 

I used to play on ps5 but on the ps4 version cause i like the controller more. Since the new update released I downloaded the ps5 version to try out 120 fps.

My screen isnt adapted for 120 fps so I wanted to go back on ps4 version but smh i cant connect, it says : this account is already connected on another device. 

How can i disconnect myself from the ps5 version so I can still play on ps4 version?

thanks 🙂