I've found that if you re-size the dialog box, it all becomes visible / usable. For some reason it renders too small (MacOS Catalina)
I suspect that this only applies to Macs, but the latest version (2.3.13 r113) now allows zooming from the trackpad (2 finger scrolling up or down). However..... a 2 finger tap is a right click and LPub3D seems to be very VERY sensitive to 2 finger gestures. The upshot is that whenever I right click on an item - it zooms in (or sometimes out) massively. It's alsmost unusable as you have to be soooooo careful not to zoom! Pinch would be a better option for zooming I think?
Trevor - firstly thanks very much working on this! I use lPub for all the instructions...