I've noticed playing around with custom systems in Ubox² that when I place planets from the random planet generator as well as taking pre-made planets like Earth and then heat them up to get random terrain and then save the simulation close the current simulation.
When I load the simulation, I notice that my Red Dwarf's (M star) temperature goes up from 2900 K to a K star, my rocky planet's temperature resets to temp it had when I placed it and the texture turns into the generic Ubox² rock planet texture.
Btw why doesn't Ubox² natively supports Red Dwarfs under 3000 K like c'mon 76.45% of the stars we found are Red Dwarfs and most of them have a temp under 3000 K.
Generic rock planet texture