Joomla portal shows HTML-Code in case description

Hi there,

I have seen several threads with the issue that the CRM shows HTML-Code in the case description instead of text.

Despite I am not affected by this issue I have the similar problem in the Joomla customer portal, when an email was sent in from Outlook 2016 to CRM, which automatically creates a new case.

I have attached a screenshot of a case.

Does anybody have an idea what is causing this issue?

Thanks in advance!