Outlook 2013 IMAP not syncing new emails

Outlook 2013 IMAP not syncing new emails

For some reason, the IMAP account I have set up in my Outlook 2013 doesn't update new emails.
Even forcing it to "send / receive emails" doesn't result in any new emails appearing in the inbox.

If I log into my webmail, I can see the emails sitting there, so not sure why they don't appear in outlook.

If I can't fix this, obviously I can't use the email system going forwards.

Thanks.