Got the same issue here on Kubuntu with when activating transparent background in Konsole with an AMD GPU (flickering of background between transparent and solid).
It only started happening when I switched to Wayland. X11 does not share the issue.
I managed to fix it in Konsole somehow by switching to another apperance theme in the profiles configuration (you might see there that, for some reason, Breeze is duplicated, which I suspect is what responsible for the flickering).
Got the same issue here on Kubuntu with when activating transparent background in Konsole with an AMD GPU (flickering of background between transparent and solid).
It only started happening when I switched to Wayland. X11 does not share the issue.
I managed to fix it in Konsole somehow by switching to another apperance theme in the profiles configuration (you might see there that, for some reason, Breeze is duplicated, which I suspect is what responsible for the flickering).