I disabled SMT to avoid meltdown attacks, so I added ‘nosmt’ in /etc/default/grub on Proxmox. Currently I’m using a Xeon E3 1275 V2 which has 4 cores, but since nosmt disables hyperthreading, I’m not using 8 cores. I do think you’re right though, this problem hadn’t appeared before and I believe only started to happen when I started messing around with the amount of cores the CPU has. I’ll test it out and keep you updated! Thanks for the advice!