U=R*I vs. Lightbulb with 40W pulls 40W no matter how high the voltage is

I my have missed something in the earlier posts but I would approach the problem differently.

If I have a lightbulb in my house with 230V and 40W

If we assume for a moment the lightbulb resistance does not change.

Power = E² / Resistance

40 = 230*230 / R

R = 1322.5 Ohms

If the same lightbulb was powered by 24 Volts:
Power = E² / Resistance

P = 24*24 /1322.5

P = 0.4355 Watts

One must remember for a constant resistance power increases / decreases with the square of the voltage.