Hot sauce still fermenting after boiling. Am I doing something wrong?

Hi everybody!

I am encountering an issue with my hot sauce continuing to ferment even after boiling.

My process involves fermenting the ingredients in a 3% brine solution for two weeks. After that, I would blend the mixture with some of the brine, add vinegar and sugar for flavor, and boil it for approximately two to three minutes. After cooling the mixture overnight, I measure the pH, which typically ranges from 3.3 to 3.4. Based on this pH level, the hot sauce should not undergo further fermentation.

However, when I bottle the hot sauce and store it at room temperature, I observe bubble formation in the bottles a few days later. Upon opening the bottles, I can hear the release of gas.

I am puzzled as to why this fermentation is persisting. I have followed this process in the past without encountering similar issues.

What am I doing wrong? Any help would be appreciated!