Been using Avast for a while and have been really happy with it. No troubles. Then a couple of days ago, after I run the smart scan (and after hitting ‘resolve issues’) it leaves the red x and says there are performance issues that need to be resolved.
This sounds like something coming from the CleanUp tool which is a paid product.
Try removing CleanUp, re-run the scan and see if you still have the same problem.
This should help you: https://www.youtube.com/watch?v=NIlmAUXecYg