u/Aura-Beast

It has not been a while since i made the PC i aseembled it myself and had crazy troubles putting the CPU air cooler because i made a Mini AtX build. For some reason i feel the thermal paste has not been working properly. First i used to get ideal temps aroung 55-56 turns out the air cooler was not fully tight (Didn't understand because of the spring below the screws). I fixed it the temps were around 45-46 idle. Now the temps are going to 58-60 idle and i for some reason feel the thermal paste has dried up and my case is heating up like an oven even when i'm playing a non demanding game like FC 26. What could be other reasons for this rise in temps?