Mac mini freezes when switching between 2 screens

FWIW, it is best that you get an additional drive for local backups. For one, iCloud is not designed with backing up in mind as is meant for sharing data between devices. Second, having a local backup insures that you will always have access to the backed up data because cloud connections depend on internet connectivity which may not always be there and may not be there when you need it the most.

However, the video issues may have more to do with the connections to the displays than anything else. If you are using the cables that came with the displays toss them and get high quality, certified cables to replace them and get them as short as possible to connect to the displays.

Well your problem may be caused by 1 of many things. However the first thing I see is:

"Low disk space - This computer is running low on free hard drive space."

This is because you purchased a minimally spec'd Mac mini. So what you need to do is to move larger libraries to an external HD to preserve space. If you have your photos, music or movies libraries stored on the Mac mini they tend to take up a lot of space. If that is the case, move these to an External Hard Disk. Apple explains how to move the Photo's library in Move your Photos library to save space on your Mac. The process is the same for music and movies. Once done double click the libraries in their new location and that will tell the apps where they now reside. Once you have done that verify in the settings that the library is in that new location. Once you have verified the location then you can delete the libraries from the old location and finally empty the Trash and for safe measure restart in Safe Mode.

Next, I see you have Malwarebytes installed, which is okay however I also see you are using its VPN functionality. My recommendation is to uninstall Malwarebytes (ensure the VPN is uninstalled)and then restart the computer.

Once you have fully uninstalled Malwarebytes please test to see if the switching issue is still there. If it is gone then you know the VPN was probably your issue. As a general rule never ever install third party VPN unless your employer demands it and in that case they will supply a high quality (and costly) VPN.

I would recommend downloading and running EtreCheck (EtreCheck.com) and posting the report to your desktop. Then when you reply to this message attached the EtreCheck report from your desktop. This will give us an idea of what has been installed that may be causing that issue. EtreCheck is completely safe and does not include any personal information.

On the bottom of the box where you will see some icons, one is for attaching files. Locate it and attach your report.

Keep trying you will get it! Sorry we do not post personal info (e-mail addresses) on a public forum.

NEVER EVER use your Time Machine External Hard Disk for adding additional data. If you are going to move your Photos library to an external HD then get another such as the OWC Mercury Elite Pro. Why, very very simple so please read on. ALL HD's die and if you have your Time Machine backup and your photos library on the same External Hard Disk when that HD dies your Photo's library as well as its backup is gone forever!!!!!!!!!! DO NOT be penny wise and pound foolish, you will regret it.