Some emails not displayed in IMAP account

Evenin’ all
I have a strange issue which has only just manifested after at least a year of using eM Client whereby a handful of emails are not displaying at all within the client but are present within the folder on the mail server and are displayed when using Outlook or the WebMail client within MDaemon - albeit it only displays the mail headers with no content. Anyone else experienced this and can shed some light? I’m on the latest version and have also tried switching to viewing emails as plain text but with no change. Any help is appreciated.
Thank you.

It could be some corruption in the message database. In eM Client, right-click on the folder that contains these messages and choose Properties > Repair. If it is a Gmail or Gsuite account, right-click on the All Mail folder instead.

Hi Gary, many thanks for your response
That was one of the first things I tried. I’ve also since stopped keeping an offline copy of the database as the mail server is local and so network speed is not an issue. I disabled the offline feature before renaming the old database directory to ensure that all was flushed and created afresh (albeit empty).
Just to provide a little more background info, it’s connecting to an MDaemon server and the IMAP account I’m using with eM Client is purely for monitoring the SPAM folders/filters.
The only common feature between this handful of emails is that they’re not displaying any HTML content when I view them in Outlook or via the web client.
Thanks again.