Numbers on iOS has switched position of currency symbol

Returning to work on a Numbers spreadsheet since the latest iOS upgrade, all my pound sterling entries suddenly have the £ symbol at the end of the figures. So instead of reading, for example £100, the entry reads 100£.

Not only has it done this in my current spreadsheet, I checked back five years and they've all switched.

i checked the Currency format and it says British pounds.

Can anyone explain what has happened and how to correct it?

Thanks.