Unable to save 'Favorites/Bookmarks' in Safari on new MacBook Air

I recently purchased a new MacBook Air and transferred all my data from a Windows laptop. Since that time my favorites/bookmarks will not save in Safari. If I delete one, it comes back after I shut down Safari and if I add one it does not save when I close Safari. I spent about an hour or so on the phone with Apple Support and they could not find the issue. I even spoke with a level 2 person. Everything you find on the internet has been tried and the OS was deleted and reinstalled. Nothing has worked. I'm hoping someone in this group has had the same the issue and got it fixed. It's very frustrating. Thank you.

[Re-Titled by Moderator]