I can't say I've experienced any hair loss even during flare-ups. However, POTS is often linked to anemia, which can lead to hair loss. Perhaps an anemia test or some iron supplements may help? If you do decide to try iron, be careful not to take it on an empty stomach. It is very irritating.

I have experienced acute/temporary hair loss multiple times in the past, however I have other issues & severe nutrient deficiencies in addition to POTS. I do know someone with a different Syncope disorder who has experienced more-persistent hair loss at a young age.

Could you possibly have COVID? That would make your symptoms flare up and cause hair loss.

No. Im guessing it is being caused by some other issue. Maybe it will help you determine the primary POTS cause.