Duplicate Sent and Draft Folders in Thunderbird

Hello. I encountered the same problem with an IMAP account on Orange mail: there were two "Sent" folders, one of which was empty. The problem was resolved as follows:
Direct connection to Orange mail
Consultation of the mailbox of the affected account
There, I found two folders: one named "Envoyés," the other "Sent"
The "Envoyés" folder was empty. The "Sent" folder contained my sent messages. I transferred these messages to "Envoyés" and then deleted the "Sent" folder.
After closing and restarting Thunderbird, the empty duplicate folder disappeared.