Firstly - I have to take issue that you have 'no symptoms' - what the heck is an HbA1c test result in the 50s then, when if you don't have diabetes it will be less than 42? A symptom is purely anything that indicates there's summat up here.
Inflammation anywhere in the body - yours happened to be noticeable but when it's summat going on internally which you can't see and causes no pain everyone's clueless 'why' - it, without fail! - causes the BG to increase.
(See, if you are a girl you find this out when you have diabetes and reach puberty - cos every month for the next 40 odd years your BG is going to tell you 'there's something going on internally that nobody can see!')
It wouldn't be any surprise that your HbA1c - which measures exactly how much unused glucose in your bloodstream has physically attached itself to your red blood cells over the previous 90-ish days - would improve as the source of inflammation subsided.
The problem you have is, because you can't see inside yourself, and to achieve any A1c result over that magic 42 threshold, your BG has to be 'higher than normal' for some time, longer than eg 2 days and could easily be weeks months or years and thus causing internal damage over that time (all the dire side effects you've read about like nerve damage, kidney damage, eye damage ..... and said to yourself Pfft! not me!)
The quickest way for you to find out what's really going on day to day, is to get a blood sugar meter and use it to inform yourself - and medical advisers - what's really going on within yourself. In that way you will be able to discover what effect eating foods and taking exercise have on your level and thus be able to make informed choices about whether it's a good thing to continue eating that and doing that. As you'll most likely need to invest you own money in one and the ongoing cost of the test strips to use it, the cheapest reliable meters and strips people on this forum have found are either the SD Gluco Navii, or the Spirit Healthcare Tee 2. If you look in the 'Newly diagnosed' section of this forum you'll find out shedloads including a regime of doing the tests, reveewing the results and adjusting whatever needs adjusting judging by those results.
This is a marathon Shak - not a sprint! Good luck. 🙂