Also as I was testing this, I just realized a second bug: the Default and Green marker colors are slightly different shades of green, at least running the default Red Graphite theme.
I did notice the space workaround. But is there a reason it shouldn’t be supported without a space? For instance, I’ve been using the highlighter feature to highlight parts of words in language learning, and in some cases, being able to bold those highlighted sections is helpful, without needing to break up the word using a space.
It’s a commonmark rule, probably introduced to avoid having too many false positives.
As you can see in the common mark dingus, the markers are ignored when nested