I set up a spare PC with Kubuntu Linux. That OS’s default browser is rekonq. I tried Parchment with it, and it didn’t work:
Is that just a window width issue?
Maybe. My report was evidently premature, because I tried it again and it worked. I know the problem illustrated above happened more than once, but I didn’t change anything on purpose. I don’t really know anything about Linux or KDE.
But, evidently, Parchment does run in rekonq, so whatever the problem is/was, it’s not really of concern.
If it happens again please check the error console so we can get a little more info about what’s going on.