[Fyron]

When the setting for "all players planets the same size" setting is enabled, planet values for HWs only vary by a few percentage points and the planets are definitely the same size... Perhaps post a savegame file where this happens, along with the settings you used for that game, so that we can verify what you see happening?

Were you using a mod of some sort? It is possible that you might have had a smaller than normal HW or other players might have had a larger than normal homeworld if you played with FQM and a bad homeworld start, which is expressely forbidden in the readme.txt and modinfo.txt files. This is because FQM uses small moons, which can be chosen as HWs on a bad planet start, resulting in the actual "planet" of the sector being chosen as the homeworld instead. This includes mods like Star Trek Mod that incorporate FQM. Average and good homeworld starts are not affected in any way by FQM, and they should not be in STM unless you made some changes to the planet and system data files.

No mod can cause different players to have vastly different valued planets though... All homeworld planets have around 80%, 100% or 120% value, depending on the quality of the planet selection at game setup.