I was just going to update my comment. After using it for a couple of days, I found that it is only on the Source's Detail Text tab for Research Notes and Comments. I apologize for the confusion.
To respond to robertjacobs0, this was not from a gedcom file. I was copying/pasting directly from MS Notepad. Thanks for your response
I don't know if this makes any difference, but on Notepad my font is Tahoma, Regular 12 and Western Script. I know that RM uses Times New Roman, but that shouldn't make any difference. This only started a couple of days ago when I installed the RM update.