Spurious character in Markdown?

[NickLocke]

This may well be something I am doing wrongly. I have some nested !INCLUDE which are correctly bringing in the content of the included files. However, the final Markdown isn't identifying the level one headers as such - they just appear as plain text. Upon closer inspection I can see that the first character on the line isn't the "#", it is actually what looks to be an invisible character with, I think, the hex code EF. That character is not in the included source MD file.

If I insert a blank line at the top of the source MD file, before the "#" then the EF character doesn't appear and the resultant Markdown works as expected. However, including a blank line in the including file (ie before the !INCLUDE) doesn't have the same effect.

The workaround is to add a blank line at the top of each MD file, but that feels a bit odd. As I said, I suspect I am missing something very obvious.

Thanks, Nick.