ZDoom

Oh well, I'll just remove the part of the map that needs it. Thanks.

As expected. Too bad that I don't really know what to do about it, it's a design flaw in how the transformation is set up and this cannot easily be undone

Just tested with Boom Scrollers. Has the same bug.

Does this also happen with Boom scrollers?

The problem here is obvious: The scroll offset is applied to the texture before rotating it. Sadly the entire implementation of texture translations wasn't done that well. The order of operations is not really what one would expect from how rotation is done normally...

Post an example map, please!

The scrolling floors using specials 201+ will scroll in the wrong direction, but still carry in the right direction, of the floor texture is rotated in UDMF. e.g. if I turned the floor texture 180 degrees, the texture will scroll opposite to the direction it's carrying.