Turns out the reason why the Geofilter wasn't working because it was still assigned to the old Playstation, not the new one. Simply deleted that, and added the PS5.
Bit of a schoolboy error on my part - apologies for that. I only have the Geofilter map on my dashboard, and completely forgot that you had to assign devices to it.
Still, hopefully it might stop others repeating the same mistake. Cheers