Keeps Restarting after Catalina UPDATE!

Please navigate to the Mac App Store or navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.

When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again. 

For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211

A Troubleshooting Procedure that may Fix Problems with macOS El Capitan or Later

You should try each, one at a time, then test to see if the problem is fixed before going on to the next.

    Be sure to backup your files before proceeding if possible.

1. Shutdown the computer, wait 30 seconds, restart the computer.
2. Disconnect all third-party peripherals.
3. Resetting your Mac's PRAM and NVRAM
4. Reset the System Management Controller (SMC)
5. Reset your Startup Disk and Sound preferences, if needed, after resetting the PRAM.
6. Test in safe mode to see if the problem persists, then restart normally.  Use safe mode to isolate issues with your Mac and Playing Safe - what does Safe mode do?
7. Repair the disk by booting from the Recovery HD. Immediately after the chime hold down the Command and R keys until the Utility Menu appears. Choose Disk Utility and click on the Continue button. Select the indented (usually, Macintosh HD) volume entry from the side list.  Click on the First Aid button in the toolbar. Wait for the Done button to appear. Quit Disk Utility and return to the Utility Menu. Restart the computer from the Apple Menu.
8. Repair permissions on the Home folder: Resolve issues caused by changing the permissions of items in your home folder.
9. Create a New User Account Open Users & Groups preferences. Click on the lock icon and enter your Admin password when prompted. On the left under Current User click on the Add [+] button under Login Options. Setup a new Admin user account. Upon completion log out of your current account then log into the new account. If your problems cease, then consider switching to the new account and transferring your files to it - Transferring files from one User Account to another.
10. Download and Install the macOS Catalina 10.15.4 Combo Update.
11. Reinstall OS X by booting from the Recovery HD using the Command and R keys. When the Utility Menu appears select Install OS X then click on the Continue button.
12. Erase and Install OS X Restart the computer. Immediately after the chime hold down the Command and R keys until the Apple logo appears. When the Utility Menu appears:

     1. Select Disk Utility from the Utility Menu and click on the Continue button.

     2. When Disk Utility loads select the drive (out-dented entry) from the Device list.

     3. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.

     4. Set the Format type to APFS (for SSDs only) or Mac OS Extended (Journaled.)

     5. Click on the Apply button, then wait for the Done button to activate and click on it.

     6. Quit Disk Utility and return to the Utility Menu.

     7. Select Install OS X and click on the Continue button.

Is it having a kernel panic? If so, read Did that Mac just restart itself? About kernel panics. Also, see If your Mac spontaneously restarts or displays a message that it restarted or shut down because of a problem - Apple Support.

Uninstall any anti-malware software. You have two installed. Get rid of both of them: CleanMyMac and AdGuard. If you don't have uninstallers, then visit the developers' websites to see if they have an uninstaller you can download. Do not use Zoom. Communications both audio and video are not secure. Read Zoom Has A Dark Side — And An FBI Warning.

AdGuard and BitDefender have both been generating crashes. BitDefender is another anti-malware product you don't need that should be removed.

Basics for Uninstalling Software

Most OS X applications are completely self-contained "packages" that can be uninstalled by simply dragging the application to the Trash.  Applications may create preference files that are stored in the /Home/Library/Preferences/ folder.  Although they do nothing once you delete the associated application, they do take up some disk space.  If you want you can look for them at the above location and delete them, too.

Some applications may install an uninstaller program that can be used to remove the application. If you cannot find the uninstaller then you could download the freeware, Easy Find, to locate files that need to be removed. The places you need to search include:

1. /Home/Library/Applications Support/ folder. Check if the application has created a folder then delete the folder that's in the Applications Support folder.
2. Applications may install a startupitem or a LogIn item. StartupItems are usually installed in the /Library/StartupItems/ folder or the /Home/Library/StartupItems/ folder.  Login Items are set in the Users & Groups preferences. Open it in System Preferences, then click on the Login Items tab. Select the item from the list and click on the Delete [-] button to remove it.
3. Some software use startup daemons or agents.  Look for them in /Library/LaunchAgents/ and /Library/LaunchDaemons/ or in /Home/Library/LaunchAgents/.

Some applications install a receipt in the /Library/Receipts/ folder.  Usually with the same name as the program or the developer.  The item generally has a ".pkg" extension.  Be sure you also delete this item as some programs use it to determine if it's already installed.

There are many utilities that can uninstall applications.  Here is a selection:

• AppZapper
• AppDelete
• Hazel
• AppCleaner
• CleanApp
• iTrash
• AppBolish
• AppUninstaller
• Uninstaller

For more information visit The XLab FAQs and read the FAQ on removing software.

Well the report indicates you have made a mess of your computer by adding multiple third party antivirus apps and cleaning apps. Mac OS does NOT benefit from nor does it require any third party antivirus, cleaning or ANY other third party "maintenance" apps in order to run well. The best solution for keeping your Mac running well is to keep Mac OS up-to-date and otherwise LEAVE IT ALONE. If you want a slow, unstable and buggy Mac then keep those apps installed!!!!!!!!!!!!!

Please locate the developers uninstall instructions for each of those apps and follow to the letter. Then restart in Safe Mode and restart again normally and retest.

Maybe run another report & post the report here?