There was a video I watched several years ago, no idea how to find it again, where this guy fucked up a motherboard / CPU with thermal paste to see if you actually can add 'too much paste.' Directly underneath the pins, wayyy too much on top, extra around the socket for good measure, smashed it all together, and the thing just... boots normally...

Kinda makes sense tho, every tube of paste I've used was marked as nonconductive, and the CPU socket should be designed such that carbon buildup is scraped from the pins when reseating, which would clear away the paste and allow good contact.