This has been ongoing for quite some time. I have several screens, and the main UI is 2560x1080 in 100% scaling.
According to Windows, my reference monitor is "above" the UI screen. And it's a UHD monitor, so it's set to 200% scaling to get roughly equivalent type sizing.
In the Lumetri panel, hitting the "dropdown" list in the Basic tab works as expected, it ... drops down.
But in the Creative tab, the 'dropdown' LUT listing drops UP. Starts on the lower UI screen, but then goes up across the upper screen of the reference monitor ... but in a TINY and nearly unreadable font sizing.
Why does that drop-down drop UP? It happens with several other "dropdowns" also, and is nearly unusable. I have to get out of my chair and get close to the screen to read the blame things!