Cant get rid of Bing

   1. Remove adware if installed on your Mac..

       Run the latest release of Malwarebytes for Mac to remove malware/adware, if installed on your Mac.

       For instructions: Install Malwarebytes for Mac v4      Uninstall Malwarebytes for Mac

       Click the “FREE DOWNLOAD” button.

       Click the “Scan ” button. Once done, quit Malwarebytes for Mac.

       Restart the computer and relaunch Safari holding the shift key down.

       Scan for Malware again.

       Additional steps  if necessary.

  2. Reset search engine:    https://support.apple.com/guide/safari/customize-your-search-ibrwe75c2a3c/mac

  3. Reset  Homepage.   https://support.apple.com/guide/safari/set-your-homepage-ibrw1020/mac 

  4. Remove unknown extensions:  Safari > Preferences > Extensions

      https://support.apple.com/guide/safari/use-safari-extensions-sfri32508/mac

   1. Remove unknown profiles if present.

      System Preferences > Profiles

      Open System Preferences,  select “General and click  the “Profiles” icon ( a checkmark on a gear) .

      When Profiles pane opens, select the unknown profile and click the minus button at the bottom.

      Section: Remove a configuration profile from your Mac

      Profiles: https://support.apple.com/guide/mac-help/configuration-profiles-standardize-settings-mh35561/mac

  2. Check proxies. SOCKS?

      System Preferences > Network > Advanced > Proxies

      Deselect   any  proxies if selected.   

   3. Restart the Mac. Relaunch Safari holding the Shift key down. 

Proxies.  https://discussions.apple.com/thread/252695178

4.  If this doesn’t help:

     Download EtreCheck: https://etrecheck.com/,run it and post the report here.

      Click  “Free Download” button,    

     Open Downloads folder, click on it to open, and then select ”Open”.

     “Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.

     Click “Share Report” button in the toolbar, select “Copy report” .

     Paste the report when you reply. This is a diagnostic test.