I personally have two of these, and know several others with them. Still fantastic and Arctic did things the correct way with their response here.
Basically the rubber in some gaskets manufactured from May 21 to March 22 can degrade and cause issues. Seems to be a pretty simple fix, and you can opt to do it your self or send it in for the repair. info all in Arctic’s site.
Website to check model number and order service kit Liquid Freezer II | Service Kit | ARCTIC
Gamers Nexus Video about issue