Issue when replying to an email in CRM

Hi ya'll!

I have a very urgent issue where I get a message prompt when sending an Email reply in CRM. 

The message prompt says: “Your changes have not been saved. To stay on the page so that you can save your changes, click cancel.” However, the email get's sent anyway so it is completely unnecessary and confusing for users. Is there a way to get rid of this? 

I am on Dynamics 365 on-premise. 

Thanks! 

/H