Please see → [Stable Update] 2024-05-13 - Kernels, Plasma 6, Gnome 46, LxQT 2.0, Nvidia, Pacman - #2 by philm
It has been known for many moons that Plasma 6 comes with a complete overhaul - that may not fit into your universe - in any case Manjaro is rolling forward.
You can do that - in the end you are better off by amending your system to the new Plasma 6 reality.