Mac OS Big Sur

Thank you for the Report and here goes >>

ExpressVPN.app

2 notifications (one scheduled) >> Point # 2 A - Commercial VPNs should only be used if Mandated by Corporate Head Office for working remotely. Otherwise - ones Privacy and Security touted by the VPN is suspect

CleanMyMac >>> Disk Cleaner, Optimizers, Un-installers, etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation.

1 - The VPNs might be used to access sites in other countries but at a cost of $$ to purchase, giving up your Security & Privacy despite what the VPN is touting it is doing. After all, they in business to make more money and use your info for whatever purpose they decided. That and it will will slow the ISP Speed and may have direct impact on your issue.

2 - CleanMyMac - very well documented on these ASC Forums as an invitation for disaster for the reasons presented above. Strongly suggest removing as per Developers Instructions It too comes into play with the OS and your issue.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS.

Suggest downloading the Application Etrecheck directly from a Trusted Developer and well Respected ASC Contributor. The application is free or paid from added features. Run the application with Full Disc Access ( Security & Privacy - Full Disc Access ). It will take a Snap Shot -  both the hardware and software. The Report will Not Reveal Any Personal Information. Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Any Third Party Applications that will interfere with the normal operation of the OS, alter, modify, remove or delete or attempt to do so is an invitation for disaster and may require a Reinstallation of the OS.

Ok, the CleanMyMac was running on previous version of macOS - right ?

Well, this application >> CMM << may have damaged the previous version of macOS by removing elements of the OS, corrupted or modified elements of the OS .

When the computer was upgraded to Big Sur, the corruption, altered and modified elements of Previous OS were carried over INTO the New OS Big Sur.

The computer maybe experienced the effects of what damages occurred previously but only appear in the Big Sur upgrade.