LUI, new computer, MRS window resize

After I upgraded to (1) OSX Catalina and (2) a 16-inch MacBook, I am facing a following issue with LUI (using LKB-FOS). A simple MRS window won’t show me all its contents and won’t resize:

Before clicking on x4[x]:

Screen Shot 2021-02-03 at 2.23.21 PM

After clicking on x4[x]:

Screen Shot 2021-02-03 at 2.24.01 PM

Dragging the window’s corner does not lead to anything.

Is there anything I can do about this?

Could this one also be related to the retina display having twice as many pixels? Again it sounds like something thinks the contents is twice as big as something else thinks it is… I use a MacBook with retina display also, with OSX Catalina on it, so I would have thought I would be seeing the same problem, but I’m not…

Maybe that I am using 16-inches screen now? My previous one had retina but was 13-inches.