Mouse Frozen in Upper Left Corner

Add-on anti-malware is pragmatically indistinguishable from malware that just doesn’t want to share the system. Both can cause weird problems. There can be other potential surprises with anti-malware, too.

Boot into Safe Mode and test, then remove the add-ons per the vendors’ instructions and reboot test. See if things work better.

As for the add-on mouse, that could be a problem with macOS, with the add-on anti-malware or add-on cleaners or add-on VPN clients or such, with the add-on apps necessary for that mouse—some mice and some mice-related apps have issues, some have updates, and what might apply here would be more apparent with some info on the mouse vendor and model—and some mice just fail.

We don’t know what you’ve tried, what you haven’t, nor what mouse or other add-ons might be present her. Not unless those details are included in what’s been posted.

To post an inventory of what’s present, download and run EtreCheck, open a new reply here, press the button that looks like a printed page to get a text input box big enough to paste the hardware and software configuration report here. That’ll usually provide a good overview of what’s installed and what’s not, and sometimes can find unrelated issues such as failing hardware.

Please use Troubleshooting wireless mouse and keyboard issues

Try another mouse. Most any USB or generic wireless mouse will work with a Mac for troubleshooting and/or to replace a belly-up Apple mouse.

Also, there is no need for third party AV-ware. If fact, most will actually do more harm to macOS than good.