[shrikant]

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?

[bestham]

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.