I have a normal (not 4k) 24" monitor with a resolution of 1920x1200 (see attachment/picture) set as my primary display (I don't know if it matters if the built in monitor or the external monitor is set as primary).
When the HSL windows is moved to the internal monitor the problem is fixed instantly. But if i close the window and open it again, the problem is back (until I move the window to my external monitor again). Although, this doesn't happen every time I try to use the HSL-adjustment window, but most of the time. It appears to work better some days...
Can this problem be connected with the lag in the layers- and curves window? I'll try to explain what i mean. When I try to use the levels adjustment window there is almost always a lag before the histogram appears in the window (the same thing happens in the curves adjustment window), sometimes the lag is a couple of second and sometimes I have to close the window and open it again a couple of times. Can this lag somehow effect the HSL-window when the interface is loading to my screen?