Some details would probably help.
If you are still getting them I suggest doing a screen capture and attach it to your next post.
Well Avast One is a new Antivirus version from Avast, not as suggested by your internet searches "The internet indicates this thing is some sort of a browser add on." I suggest you check out this
Avast One FAQ.
Avast does also have an browser add-on also, completely independent of the antivirus.
What have you done that doesn't impress you ?
I still use Avast Free (there is also a free version of Avast One) and have been for over 17 years and no infections.