IOS 14 holiday calendar wrong country!! UK user

Hi all. IOS occasionally throws up random problems for me. Changing the international dialling code of uk friends and family in my contact list to Belgium is an interesting one and seemingly I'm not alone, but this latest one has stumped me.

Following ios 14 update i now have a US holiday calendar (subscribed?) that i cannot seem to delete or change back to UK. I've checked the region on my phone is correct, i've looked to see if the calendar account is visible/capable of being deleted, i've even wiped and reloaded the phone from its most recent back up, nothing has changed it.

Apple support have tried to help looking at email and calendar accounts, neither of which have the US holiday calendar subscription showing.

Any bright ideas out there??