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).
I imagine ‘Forge’ like you pronounce, well, forge, and ‘jo’ like you pronounce Joe*.
*Language and accent differences may apply, but hey, that’s the beauty of the world’s diversity!