Somehow the cover damaged the heatsink (I think), and thus seeming to have leaked here and there. I discovered this while replacing DRAM with XMP DRAM (which apparently isn't supported.) Double bummer
HP V6 Gaming DRAM DDR4 2666MHz 16GB CL18 con Heatsink : Amazon.es: Informática
TEAMGROUP T-FORCE CARDEA II 512GB with DRAM and Gaming Fin Heatsink 3D NAND TLC NVMe Gen3x4 PCIe M.2 2280 Gaming Internal SSD (Read/Write Speed up to 3,400/2,000 MB/s) for PC Desktop TM8FP5512G0C110