Interesting. This is certainly not the first time there have been markdown parsing inconsistencies between clients on Lemmy, the most obvious example being subscript and ^superscript^, especially when multiple words ^get used^ or you use ^reddit ^style ^(superscript text).
But yeah, checking just now on Jerboa you're right, it does display correctly the way you did it. I first saw it on the web in lemmy-ui, which doesn't display it properly, unless you use the triple backticks.