Computer locks down at screen saver

Well user choice

But a caveat to consider before going that route.

If the issue is a Third Arty Application installed and used on this computer s the Real Issue, reinstating the OS may not solve the issue

Reinstalling the OS over the Existing OS will only correct missing or corrupted elements of the OS.

You may consider looking at the below and see of any of the Listed Application apply to this situation.

Any Third Party Applications that will interfere with the normal operation of the OS,  is an invitation for disaster and comprise the Operating System

Certain Applications maybe available on the Apple Apps Store - this only means the Developer is prepared to pay Apple a portion on each sale. What the Application may do to the computer is up to the User to check this out before purchase

Any of the below should be removed as per Developers Instructions 

1 - Disk Cleaner 

This will include CleanMyMac , 

MacKeeper,

Dr Cleaner Pro Plus

Open Cleaner one Pro

2  - Third Party Security Software 

This will include BitDefender , 

This will included Norton Antivirus 

 Sophos Av Software

Intego AntiVirus

 McAfee, 

Avast AntiVirus

Ad Guard,

 Webroot ,

 ESET ,

 Avira ,

AVG AntiVirus  

 avira antivirus 

Trustee  

AntiVirus for Mac

F-Secure

Securemac

Read some of the posting and arrive at your own conclusions.

The The Built in Security  is all that is required.

Part 2 of 2

Specific to CMM, MacKeeper and Dr Cleaner Pro Plus 

Some Contributors suggest restarting in Recovery Mode and choosing to Reinstall the Operating System over  the existing installation. 

This may or may not replace elements of the Entire Operating System including the Home Folder ( User Account )  and replace any corrupted or removed elements of the Operating System and make thing right.

Then there are Other Contributors ( like myself ) would suggest  from this link Use Disk Utility to erase a Mac with Apple silicon.

For Intel computer >> Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS

Thereafter to start from scratch and install all Required Application directly from the Apple Apps Store or Directly from the Developer.

If going this route - I suggest Not using Startup Assist to migrate things back as this will probably Re-Introduce the existing  issue that existed when the TM Backup was made 

Has the User enable Hot Corners ?

Or is this some Other Type of " Locks Down " you are referring to ?

Use hot corners on Mac

You can use the corners of the screen as hot corners, to quickly start actions when you move the pointer to a corner. For example, you can start the screen saver when you move the pointer to the top-left corner of the screen, or lock the screen when you move the pointer to the top-right corner.

Tip: By default, the bottom-right hot corner is set to Quick Note, so you can quickly open a note to jot down your thoughts at any time. See Start a Quick Note.

1. On your Mac, choose Apple menu  > System Settings, then click Desktop & Dock  in the sidebar. (You may need to scroll down.)
2. Click Hot Corners on the right.
3. For each corner you want to use, click the pop-up menu, then choose an option, such as Notification Center, Launchpad, or Lock Screen.
4. To use a modifier key with the hot corner, press and hold the Command, Shift, Option, or Control key, or a combination of these keys, while viewing the pop-up menus.
5. Click Done.

Seven steps to trouble shoot and strongly suggest starting from the first and work ones' way down the list.

If you reach step 5 - Test in the Newly Created Account is the same issue is presented or Not.

1 - Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Safe Mode will also eliminate Third Party Software, extensions and drivers from loading. It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance 

3 - Does the issue present in this mode ?

4 - Sometimes a Safe Boot followed by a Normal Boot will just put things right.

5 - If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

6 - If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

7 - Download the Application Etrecheck directly from the Developer.

This is a Diagnostic Tool that makes no changes to the computer.

It makes a coherent and readable inventory of both the Hardware and Software used on the computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Problem: Other problem

Description: MacBook on Ventura freezes after a few minutes of inactivity.. Screen saver not activated

Hardware Information:

  MacBook Pro (13-inch, M1, 2020)

Q - Antivirus software: Apple and Cylance

A - Remove as per Developers Specific Instructions 

https://www.blackberry.com/us/en/products/cylance-endpoint-security/cylance-protect

The The Built in Security  is all that is required to protect the computer.

There is Adware & Malware which will affect the computer and is generally downloaded from “ Shady “ Websites or Developers who Inject this software into the download.

A - Specific to Big Sur macOS 11 and above.

The Operating System resides in a Sealed and Read Only Volume that can not be opened by the User.

Should Malware be installed, it would ONLY Affect the User Account in which it ws installed in and not the Whole Operating System

System Extensions:

Q -   [Running] CylanceEsExtension - version 1.4.100.466 (Cylance, Inc. - 2021-01-14)

    Application: /Applications/CylanceES.app - version 1.4.100.466 (Cylance, Inc. - 2021-08-04)

    Description: This system extension checks for malware and stops it from infecting the machine.

[Other] com.cylance.agent_service.plist (Cylance, Inc. - installed 2021-01-14)

    Executable: /Library/Application Support/Cylance/Desktop/CylanceSvc.app/Contents/MacOS/CylanceSvc

  [Loaded] com.cylance.cylancees.plist (Cylance, Inc. - installed 2021-08-04)

    Executable: /Applications/CylanceES.app/Contents/MacOS/CylanceES

  [Running] com.cylance.cyoptics_service.plist (Cylance, Inc. - installed 2021-08-04)

    Command: /Library/Application Support/Cylance/Optics/CyOptics.app/Contents/MacOS/CyOptics -t Collect

 [Running] com.cylancePROTECT.plist (Cylance, Inc. - installed 2021-01-14)

    Executable: /Applications/Cylance/CylanceUI.app/Contents/MacOS/CylanceUI

Download the Application Etrecheck directly from the Developer.

This is a Diagnostic Tool that makes no changes to the computer.

It makes a coherent and readable inventory of both the Hardware and Software used on the computer 

The application is free or paid from added features. 

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

you can try System Settings > Lock Screen and change "Require password after screen saver begins or display is turned off" to "never"

Thank you for the Report 👍.

We will dissect it in detail. 

Will get back to you soon.

Sorry but the Instruction could not more clear.

Incase it may have been over looked earlier

A - Remove as per Developers Specific Instructions