Newly added email account, disappears after restarting Thunderbird.
I have added a new IMAP email account, both automatically, and by inputting the server information manually (auto-config) several times, and the account is created in the left-hand panel, inbox, draft, sent, trash folders, etc, but after I close Thunderbird and reopen it, the account has disappeared. I don't want to reinstall Thunderbird in case I might not be able add any of my existing email accounts.
Screenshots attached. (email@example.com was the added account)