Both screenshots are taken from exactly the same build. The only changes in the build have been a big increase of power (from 1890 to 2163) and dark mastery (from around 4700 to 5266), so with higher stats and with the overall increase of level impact on spells, I was expecting an increase in the effect of this spell. However, it’s effect has gone down.

Could you look into this to see what is happening? Thank you very much for your time and attention.

I have found the problem. It seems that all power increasing spells have gotten their multiplier raised to the power of 2. For example:

Abyssal Channel used a x0.75 level multiplier and now uses a x0.5625 level multiplier (0.75^2)

Deadly Accuracy used a x0.6 level multiplier and now uses a x0.36 level multiplier (0.6^2)

Divine Steed used a x0.5 level multiplier and now uses a x0.25 level multiplier (0.5^2)

I am not sure why this change. If it was to make them more powerful, it was clearly a mistake since any number below 1 to the power of 2 will give a lower result. If it was to make them less powerful to compensate for the improvement of the impact level has on spell effect, the idea of a small nerf seems sensible but the execution is terrible. Raising a number below 1 to the power of 2 will reduce it more the lower it is. That means that spells with a high multiplier such as Abyssal Channel have been less affected than spells with a lower multiploer such as Divine Steed.

So what happens with Deep Magic? That it was the power granting spell with the lowest level multiplier: x0.25. So raising it to the power of 2 makes it 4 times lower, giving a negligible x0.0625 level multiplier… I really hope this is some mistake that will get corrected, because otherwise it will mean this spell has become practically useless.