That’s a toughie, because it’s really related to Avast and how Avast was set up.
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What’s probably happened is that when Avast was installed, you installed it while logged in to your account. Avast may have asked if you wanted it to be available for all accounts, or just the current one. It probably defaulted to just the current one, so if you didn’t know what to answer, or were just zipping through the setup, that might have been selected. Or it may not have asked at all. Or it could be a bug in Avast.
When programs are set up, they have the option of making themselves available to all users on the machine, or just the user that’s installing the software. There are several aspects of the install that can be affected by this decision, including the location of files, the location of information in the registry, initial settings, and even permissions.
Since everything works in one user account, but has such a clear and definite problem in another, this “smells” like that kind of problem.
I’m tempted to say try installing it again using your husbands account, but I don’t know that that will resolve the problem, or perhaps just move it. When you to try to reinstall, do pay particular attention to whether or not it asks to install for all users or only the current user. Select all users, of course.
And if that doesn’t work, I’d check with Avast’s technical support and see if they have suggestions for this issue.