https://www.gamespot.com/articles/pubgs-anti-cheat-update-delayed-for-pc/1100-6456591/

PUBG developer PUBG Corp. planned to release a PC update focused on new anti-cheat measures today, February 5, but that update has now been delayed. The studio said it discovered an "unexpected issue" during compatibility testing, and has thus made the decision to push the release to sometime later.

As announced earlier, this update is expected to add a new anti-cheat feature that will "block different helper programs that alter the graphics or aid in gameplay in some way." One popular piece of software that will be blocked with this update is ReShade. You won't face a band if ReShade is detected on your system, but if you won't be able to play PUBG so long as it's installed. You have to uninstall ReShade, along with any other prohibited program, before getting back rights to play PUBG.