Unexpected "figure spaces"
In some headers I am finding "figure spaces" added to the end of lines even though I've never asked for them. I can see them using the "view invisible characters" function.
The really weird part is that
1) I can't select or delete them
2) They don't seem to actually add space.
3) They seem to be breaking my TOC entries by adding extra tabs or extra newlines.
So for instance I might have something that looks like:
"Transfers#"
where the # character is the icon for the figure space invisible character. See the image below.

Any ideas where these are coming from and how I can get rid of them?
