Problem with using emojis in the body of campaigns

I have an off the shelf updated version of phpList on my server. I’m using the built in CKEditor.

If I paste in an emoji to the body of a campaign, everything looks good in the visual editor, but when I save the draft, the emoji and everything typed after it are lost. If I load the source view, use the html code for the emoji and then save, everything seems to work fine and the emoji appears in the visual editor as it should. If I then save again, I get the original problem unless I return to the source view, delete the emoji and replace it with the html code.

Is this some sort of problem with encoding? Any tips about what I need to do to track down the cause of this problem and resolve it?

Thanks in advance for your help!