Inbox shows no message but they have been received

[acbq]

Inbox is problematic !  From roundcube, I can send and receive 'to myself' without any problem.  I can also send from roundcube to any E-mail and it works.   However, if a send from, from instance, Thunderbird or any other E-mail, no message in the Inbox file !  A check with outlook office from the office platform ----e.g. portal.office.com website --- indicates that messages have been received in fact.  So they should be in the Inbox of Rouncube.  Any solution ?