Norton can't remove threats it finds

This Norton window titled Action Required pops up all the time with a list of threats that it can’t remove. The only action is to rescan, but that doesn’t help. When these threats were on the secondary drive in a fake email program, I just went into the listed files and deleted the contents, so then Norton gave itself credit for removing these. But now these things have invaded my real email program. I did chat with a Norton tech who removed another program but not the threats, even with the Power Eraser. This just keeps on occurring so that for each threat the status says “Remove Failed.” I got really tired of having to go and remove these myself when Norton is supposed to do that. Sometimes Malwarebytes or Kaspersky (the program the tech removed but I put back) removes these, but not very many. These are mostly Trojans and JS Downloader. It is really irritating to pay for a program that is supposed to take care of these things, and then have to do it myself. The last bunch is still there because I got tired of doing that. Thanks in advance for any suggestions…