Did you copy the full profile folder as this is usually not recommended ?

You can copy certain files with Firefox closed to the current profile folder to transfer or recover personal data. Note that best is to avoid copying a full profile folder.

• bookmarks and history: places.sqlite
• favicons: favicons.sqlite
• bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
• cookies.sqlite for the Cookies
• formhistory.sqlite for saved autocomplete Form Data
• logins.json (encrypted logins;32+) and key4.db (decryption key;58+) for Passwords saved in the Password Manager
  key3.db support ended in 73+; to use key3.db in 58-72, make sure to remove key4.db
• cert9.db (58+) for (intermediate) certificates stored in the Certificate Manager
• persdict.dat for words added to the spell checker dictionary
• permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
• sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)

No I never import full profile folder but I use the tweak from Palemoon team to do the transfer to FF and all work well the only issue I get is that when I start Firefox it create a folder named "Palemoon" with only cache repertory and some files.. I can delete it but I have to do each time..

I did that there is few years ago 2/3 years I do not still have Palemoon now... I'm lokking a way to fix that without reinstalling all FF .. I use Portable version..

Thanks