There is at least one email message which is not being shown in the inbox list of messages, but is being shown when I search for that email.

I have previously received another email from the same sender, and that message is being shown in Inbox.

Moreover, when I mark this strange email as being unread, it does not show up in the Unread message area. If I mark  other normal email as unread, they show up in the unread area.

This email in question does not have any attachments, and was from gmail.

Is this a bug in Zoho mail?