We have a custom piece of code that when you create an email from a Case it uses the XRM lookupObjects that takes a field from the case (Case Type), and uses this to filter from a list of Standard Responses. Problem is it doesn't always apply this filtering on the first attempt, but if you close and reopen it works. This was entered as a known issue by the MS support Team (4878440), and was suggested to enter an idea here so others can vote it up. Hopefully, this just gets fixed without having to have people vote for it.