Search Function Not Working Properly

When I start a search in my emails, regardless of the folder, Zoho is not showing me all my results. E.g if I search Rosy, emails to or from Rosy before a certain date don't appear. I have no archived emails and I am conducting the search properly. I know that it is a fault with Zoho because when I search the emails on my phone, a list of the missing results appear but with the sender details, subject line and first line of the message. It's only when I click the email that all this information becomes available to me.

Is there a way to resolve this issue as I often need to access old emails.