I have Avast Cleanup Premium running on a desktop I now use to work from home. I typically run the Maintenance scan process daily. A couple weeks ago I noticed that it no longer seemed to be finding any Browser Cache, Tracking Cookies, & Browsing History to remove. Also the little check boxes are grayed out. It still does find Broken Registry Items, Broken Shortcuts, & System Junk to remove. It doesn't matter which browser I use but I favor Firefox. Occasionally it will work right after a boot time scan. I am currently running Win10 Version 10.0.18363 Build 18363.
I try to find answers on the forum before starting another thread but it looks like others have had this same issue in the past.