Have you ever felt a burning sensation in your chest or throat? That is called heartburn. Oftentimes you can taste stomach fluid in the back of your mouth. If this is something you experience more than twice a week, there’s a chance that you may have gastroesophageal reflux disease or GERD.
https://www.bizjournals.com/atlanta/news/2018/11/05/what-is-gerd-and-what-can-you-do-about-it.html
What is GERD and what can you do about it