Reverse highlighted text in message being created

My wife is having a problem on eM Client where some reverse highlighted text shows up in the note she is typing and it won’t go away even if she minimizes eM Client. If she shuts eM client down, the highlighted text still doesn’t go away and she has to kill eM Client in the Task Manager to get rid of it.

Hello,

I am sorry for delayed answer, can you please send me here screenshots of this issue?

regards
Jan