Hello,
Click “Send/Receive” at the top of Outlook, then click “Show Progress.” After that, please provide a screenshot so I can check whether there are any error codes in the send/receive progress.
For now, you can try the following steps:
Close Outlook.
Open Control Panel → Mail → Show Profiles → Add.
Create a new profile and add your email account.
Open Outlook and choose to start with the new profile.
Check if logging into your mailbox with the new profile resolves the issue.