System locale is not set when changing "Language", "Formats" and "Input Sources" fields in the "Region & Language" pane of Settings

I've set the Language on my Pinephone to "English (United Kingdom)", the Formats to "United Kingdom" and the Input Sources to "English (UK)". However, I note that no locales have been set following this. Running locale from the terminal results in the following errors:

locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory

I have attached the current output to the locale command in a text file:

locale.txt