I've been on Eliquis pre and post ablation so I researched all the possible side effects.
If you look it up on Drugs.com you will find a category for "gastrointestinal". Dyspepsia (which you may be describing) gastritis, gastroenteritis.... are considered "common" 1 to 10 %. I'm sure GERD fall into that category somewhere, especially if you already have it.