[LH772] 2.9.0.21 - Compile replacement not sticking

I am trying to get the compiler to double space my content. I am entering as the Replace value and as the With value. As I do this I see what looks like one and then two space characters appear in the respective fields. I then hit save.

Going back in to edit the format I see no entries in the Replacements box.

I may well be trying the wrong approach to get the desired result but this would seem to be bit of a bug regardless, no?

This has been filed. Thanks.