Email body disappears on Outlook and OWA, if you open the email first on iPhone

I have some users which have very strange problem.

• 
  

  If they open an email first on their mobile phones (any iOS device), email body is not displayed in outlook or in OWA, they only see the attachment.

  
  


• 
  

  If they forward same email to themselves from mobile phone and if they first open on outlook, then text is back again.

  
  

What can I do to solve this issue?