GERD after vaccine, diarrhea after covid recovery

Hello. I have had mild GERD a times since I was a boy. I am a 25 year old male, active in sports and study. After receiving my second dose of the Moderna vaccine (in 2020) within days I had a painful red throat that I thought was a bacteria or a virus. Soon my mouth, tongue and nose were irritated as well with the same burning sensation, severe at times. I eventually went to a Gastologist and discovered it was caused by gas rising from my stomach.

I have heard of studies on the brain/stomach disturbances from covid. Is it possible that the vaccine and/or virus has caused my GERD to spike and to change from a liquid reflux to a gas symptom? I cannot ignore the new symptom that began three days after my vaccination.

Also if it is helpful. I recently got covid again (for the third time) and had primarily bowel symptoms. Weeks after recovery the diarrhea reoccurs on occassion.