My situation is not too dissimilar although I am not eating the ultra naughty stuff as way to scared to try!!!
I don't doubt my Hba1c as it has been rising through pre diabetes aver the years . Was 6.9 (53) at time of diagnosis although I was ill at the time of test and was on antibiotics for the week prior.
Was for an in infection in my tongue( since found out was the wrong type of anti biotic for my issue!!!) . Also had my arm in a cast for 6 weeks for a wrist injury making me less active and stressed.
Also ran the Brighton 10k the week before the test ( no training due to wrist injury) and came out of it with very sore Achilles ( still have tendonopathy)
Was putting mouth sore down to dehydration and being run down after Brighton 10k until I discovered can be diabetes related post my diagnosis.( and it reoccurred twice more since)
@Bluetit1802 are they the kind of things you refer to that can impact HbA1c?!