Had similar issues at St Ives on the way back, made moot by the train pulling in. Quite a rude staff member too; I showed her on the Government website where it said they’re only required indoors and she said “I don’t want to read it, I just want you to wear a face covering”.I was instructed to put a mask on on the (outdoor) platforms at St. Erth station this morning by someone who was apparently a member of GWR staff.
I replied “they aren’t required outdoors” and she said “they are, I’m afraid, on the platform”. I ignored her and walked away (without putting a face covering on), and nothing else happened.
Thankfully GWR staff outside of the St Ives Bay line have been applying the rules correctly, so it is probably a local area management issue. I’ve put in a complaint to GWR, not that anything will come of it.