Copy / paste can be fiddly on mobile. I opened an MR today to make the paste part a bit easier in phosh-osk-stub (another old branch finally cleaned up into a (hopefully) mergeable state):
@agx It's sad how copy and paste seems to be a pretty solved issue between GTK and Plasma on Desktop, but breaks so frequently on mobile.
I guess that's probably largely due to Phosh not being Gnome, but don't quote me on it. I'd be curious to try KDE apps on Gnome Mobile and see if it's any better...