"Search Folders" gone after renaming a few folders?

''Thunderbird 147.0.1 (aarch64, macos, m2)'' Team, After spending many many hours creating 14 search-folders that can find all of the right emails in approx. 20 "real" (local) folders. Then I renamed 10 ''local folders'' '''and noticed my searchfolders disappearing!?''' '''''Big panic'''''. Now, only the last 2 created searchfolders where there. The rest was gone. Realizing that the searchfolder config is in a file called "VirtualFolders.dat" I instantly took a copy. Restart Thunderbird: Now only 1 searchfolder was left. The copied virtualfolders.dat file still had 2 searchfolders in it but the rest is gone. There is no other copy/backup of this file. These search folders are the only thing that generated some sense in gigantic piles of email. '''''Does renaming local folders KILL Virtual/Search folders? '''''