Thunderbird not creating Sent folder on new empty account

Hello, where should I look as Thunderbird email client does not create the Sent Items folder on server when a new empty mail account is added and a mail is sent. The sent mail is instead stored on local disk in Sent Items. On the server side (postfix, dovecot) the mail folder is created under /var/mail/vhosts/domain/user where other items such as inbox is added and incoming mails are stored there. Sent items was just not created. For comparison I tried the same with Apple Mail client and it added a 'Sent Items' folder under the server path, which if I manually set it in Thunderbird will be used correctly for sent mails. What could go wrong as the server path /var/mail/vhosts/domain/user is correctly writable and the inbox can be created and also the apple client however creates also the sent items folder. With some other servers with identical setup I have not had this issue.