HI
@ka678 and welcome to the forums.
I believe that if you had a hba1c of 50 in the UK then they'll keep monitoring your hba1c for diabetes even if it returns to normal. 50 puts you firmly into diabetic territory, though at the low end. Though of course, given that it was only one test and was influenced by COVID, it's possible that they won't give you an official diabetic tag. And illness elevates blood sugars, as do certain medications (eg maybe you were given steroids while you had covid), so if you were sick for months then this is quite likely to have influenced your hba1c.
An hba1c of 50 corresponds to an average blood sugar of 8.1mmol/L. And an hba1c of 40 corresponds to an average level of 6.7 mmol/L and is one point below where you'd be considered to have prediabetes.
I'd personally argue that it doesn't really matter what the official diagnosis is. You now have the information that you need, which is that in certain circumstances your body doesn't cope well with carbohydrate. (I'm making an assumption here that your issue was insulin resistance and carbs (T2), rather than lack of insulin (T1) because your weight loss appears to have reversed or reduced your symptoms.) And frankly, if you can eat 300g of carbs and only go up to 11 you are coping with carbs much better than anyone with a T2 diagnosis on these forums

. (Though 11 is outside the normal range, you can't tell much from one reading.)
No doubt your doctor will give you an official diagnosis next time you go for testing, and I hope that that is not diabetes. But for future reference, if your figures are higher than you like, then have a look at the carbs in your diet. Ideally, your blood sugar 2 hours after your first bite of a meal should be no more than 2mmol/L than the level before. If it goes higher than that, there's probably too many carbs in that meal for your metabolism.