Dragon Master Magia cannot be summoned by ultimate fusion. Playing on windows 10
Can you be a bit more specific in what materials you were trying to use to summon magia?
Also, consider this
https://db.ygoresources.com/qa#24039
I tried with 3 blue-eyes spirit dragons and a blu-eyes chaos max as well as with 1 blue-eyes ultimate dragon and 1 blue-eyes chaos max dragon. This interaction in simply not working