Changing Star Luminosity shrinks star into nothing

[ShadowMage]

I'm trying to create a semi-realistic star system.
I take the sun as a base, modify mass and radius based on equations I've found (a la Artifexian).  But when I attempt to alter the luminosity, without fail the sun will shrink (and usually disappear) the instant I set the number.

What in the world is going on here?

[Angel Armageddon]

Physics is what's going on. When you decrease the luminosity, you also decrease the temperature, and when the temperature decreases, the stars size will also decrease, and the color will change as well.