I've got a Nokia 8 (also bought in the UK) with the Evenwell system apps as well, and I haven't noticed any unusual domains in my Pi-hole logs at home.
I wonder if it's only specific country builds that display this behaviour?
These apps can freely choose to only use the cellular modem for communication and thus communication may not show up in your firewall / proxy. In addition to this, your carrier can't distinguish legitimate traffic generated by you from malicious traffic generated by these applications.
