Blank inserted in MOBI when using italics

I have noticed that when I use italics, there are times when a blank space is inserted in the MOBI that is not in the Scrivener file. For example, “before his eyes—la rue Pierre-Ducharme” compiles with a space between the word “eyes” and the M-dash, where the M-dash is the start of the italics. This doesn’t happen just on M-dash and it doesn’t happen in all scenarios. It also didn’t happen when I compiled to EPUB or Word format. Any ideas, anyone?

When compiling to MOBI, Scrivener first compiles an EPUB, then passes it to Amazon’s KindleGen for conversion to MOBI. If you’re not seeing the space when creating an EPUB from Scrivener, then the issue is happening during that conversion stage, apart from Scrivener. Does it occur in all devices in Kindle Previewer? Could it just be related to the spacing caused by the justified alignment?