Should I just replace it then?
if it was still working fine why would you?
my first AIO was a Thermaltake Water 3.0 Extreme that i purchased in early 2014.
i ran it constantly in a gaming system for ~3 years, now it's been running at least a few hours everyday in our media center system for 4 years and still works perfectly.
next was an EVGA CLC 280 in early 2017.
used it constantly in a gaming system for 4 years, now it is residing in a friend's gaming system and still going perfectly.
many that are
anti-AIO will frantically argue against them and claim that they are a bad idea because of constant failure, short life expectancy, and leaking issues but this is not the case with your average device.
i imagine many of those...