Cannot edit Screen Time Limits (adult using own computer)

Sounds like the Cold Turkey app is also blocking Settings and that is preventing you from making any changes. It is one of the "features" of that app. Try uninstalling the Cold Turkey app, then turning off Screen Time.

toodaloo7 wrote:

I can't turn off Screen Time either, because every time I click on Screen Time on System Settings, the System Settings app closes.

I found a better blocker option (Cold Turkey),

Missed that part as being a third party app./ never heard of it— does not sound better.

For your third party app—if in doubt search the developers website or contact their: Support/Help/FAQ/Known issues/compatibility/updates/Uninstall…

Contact a third-party vendor - Apple Support

Contact a third-party vendor - Apple Support

further—

 SafeBoot Start up your Mac in safe mode - Apple Support

third party system modifications are disabled temporarily.

Login and test. Reboot  as normal and test.  Caches get rebuilt automatically.

toodaloo7 wrote:

Cannot edit Screen Time Limits (adult using own computer)

MacBook Pro 13″, macOS 15.7

Then I would turn it off.

System Settings > Screen Time > Turn Off Screen Time

Your current Sequoia is 15.7.3

Keep your Mac up to date - Apple Support

To be proactive you can file a bug report / submit your Apple Feedback here: Product Feedback - Apple

Call Customer Support (800) MY–APPLE (800–692–7753)

Thanks for the update!