Since the error was referencing KVM and i saw that old libvirt version I have updated it and recreated the libvirt file.. After doing that I saw some old VM's coming back that had not been active, but my correct one (the one that was active) was not in that list... I deleted the wrong ones and re-added (vdisk was ofcourse still there) the missing VM, worked fine.
I have also pinned two threads to the VM (and two other threads to my plex docker).
I have since both actions not seen any page allocation failure messages.. As they appeared to be there on a daily basis and it has now been stable for 48 hours these might have made a difference..