Emacs

I'm running into an issue where Emacs (Spacemacs if relevant) would complain about invalid UTF-8 characters in the temp file buffer that was generated when saving a file I was editing with EPA. Telling me to select a fallback coding system.

These default coding systems were tried to encode the following problematic characters in the buffer ‘ *temp file*’:

  Coding System           Pos  Codepoint  Char

  utf-8                     1  #x3FFF84   �  
...

I don't think this makes sense, obviously the encrypted file would have bad UTF-8 characters but why would Emacs complain about this? This file is an org-mode file that was encrypted with GPG. The warning pops up reliably a few seconds after I save, and sporadically when I'm editing. It is making it unusable because it pops up even after I select an option.

Any suggestion on where I could even begin to try fixing this?