Thanks for the snippet, but that hasn’t quite seemed to work. It is replacing the character, but still no search results, and now the original ‘M&’ search, which was working, has also stopped working.
This appears to be happening due to WPML’s treatment of the ‘&’ character. Searching for M&M works correctly, but obviously no user will know that. I have had similar issues with WPML before, and they haven’t been helpful, so is there any way to convert characters like & into ‘&’ before searching if a translated language is being used?