Something else to consider: Whenever I have PeroPero open in another tab, especially after playing a dozen nGachas in that game, everything slows down, most noticably FKG. So I generally close PeroPero these days everytime after I'm done, it's just 2 clicks away to open in a new tab later anyway. Not sure if any other games cause similar issues.

Just scanned my PC for malwares.
Many is found and removed.
Currently testing if it works.
So far don't see any problems.
Hope it continues for eternity.