my imac running on safarikeeps switching itself off

Apple Support has an article online (link below) that may be helpful:

See: If Safari doesn't open a page or work as expected on your Mac - Apple Support

Else: If you still need help:

Check your MacOS version is the newest available version:

Eg: What's new in the updates for macOS Sequoia - Apple Support says MacOS 15.0.1 is the latest.

If you have any unnecessary third party (non-Apple) apps like ad-blockers, virus-checkers, cleaners, and the like, try turning them off (or use their uninstallers from their developers / manufacturers)

For any necessary third-party apps, check they are updated to the newest compatible app.

(ie: Only Apple apps are updated automatically when you update, or upgrade, MacOS)

Thank you kindly for taking the time to reply. and for clearly describing what is happening on your Mac. Also, for expressing your viewpoint on the issue.

Sorry to hear your experience with Apple Support was not more fruitful for you.

All the best :-)