I have several Modulators shown in the Lower Zone. If I click (Open in Separate Window) on a Macro Knob Modulator, I’m presented with this window:
With this tiny, distorted window still open, I go ahead and add another modulator. The too small window is now shown at a proper size.
If I close and re-open the separate window for this same Macro Knob Modulator, it is back to the unusable tiny size.
Removing a Modulator also triggers the tiny window to be shown in a proper size.
(Cubase Pro 14, Windows 10)