Drop Shadow Tool not producing correct effects

This is a pretty serious problem, about how the drop shadows interact with a black background. The problem only seems to be present when working in CMYK, not RGB. Basically, I have created a drop shadow with normal operation (not multiply, hard light etc.) and I break it off and convert it to a CMYK bitmap. Usually the drop shadow is a bright colour and while it is converted to a CMYK bitmap, the black behind it is usually a vector curve with the value: CMYK 30, 30, 30, 100. Now as it appears on the screen is exactly how I want it to print, however when I export to a flattened bitmap, it blends the drop shadow into the black background in a way that ruins the blend and makes it look nothing like it did before the flattening. Exporting it as .pdf and leaving it layered still produces the same INCORRECT effect.

The worst part about all this is that to make it blend properly, I seem to have to select the drop shadow and the vector background, convert the selection to an RGB bitmap and then straight back to a CMYK bitmap, doing this gives me the effect that I was looking at from the beginning, but in a printable file.

I know I can't be the only one to be facing this problem as it happens with literally any colour other than white when putting a drop shadow on a black background. Why doesn't CorelDraw convert the colours into what you can see on the screen since that is obviously what you are going to expect and why do I have to put it into RGB colourspace to make it look right?

Anyone wanting to replicate the error should try this:
Create a black square, CMYK 30,30,30,100, put a circle inside it roughly half of it's size, give the circle a drop shadow of any bright colour with normal operation, 90% intensity and 35% feathering, break it off, convert to a CMYK bitmap and export the whole thing as any type of raster file in CMYK (.jpg, .tiff, .psd etc.) and once exported, bring it straight back in and put it next to your objects. You will notice that the drop shadow has added a white effect in the fade of the colours and effectively washed it out and lost a lot of intensity.
Now for comparison, if you select the drop shadow and the black square, go to convert to RGB bitmap and then change the mode straight after, back to CMYK, you will have it as a flattened image with the correct blend between the colours which is printable, the only bad thing is that your black has changed now from CMYK 30,30,30,100 to CMYK 72,69, 67, 89.

Any help on this would be greatly appreciated as it's driving me bonkers and I almost feel like I'm missing something as I don't see how Corel could have broken such an important tool so severely.