help me out ?

Soo uhhmm.. i was just reading some bl manga i found and when i was just checking out another site (not mangago, just youtube music lol) to change my music and when i went to mangago back, it automatically logged me out of my account. idk what's happening lol but when i logged in again and read the manga i was reading, and when i clicked yt music again to change my music. it again automatically logged me out??

somebody explain this problem :(