Mr_WillBuildBruhTry remounting your backplate for the cooler? Never seen a cooler just randomly come loose, even the older shoddy plastic tab coolers.
I'm actually taking the opportunity to actually upgrade my stock cooler which came with my i5 2500k, I'm getting the Cooler Master Hyper 212 Evo.
I have that cooler and so far I haven't had any issues with it, just make sure you clean off and re-apply the thermal compound because if there isnt a good enough contact with the paste and the heat spreader then that can also cause some issues, the EVO 212 also comes with a small tube of thermal compound if you dont have any.