Hi Martin, I am able to repeat that over here. It looks like they are actually behind the options dialog but they are attached to it and move with it so you can't uncover it. It does not seem to happen on High Sierra so I'd guess it's probably a bug in Mojave but I'll investigate what I can do to avoid it. Thanks for reporting it!
Thanks Finema, must have been fixed sometime after 10.14.0 . I think I've got a fix for it anyway though which should hopefully be less likely to get messed up.
Hi Martin & Finema - I've got a fix for this problem where the sub dialogs on the Options window weren't showing in full screen mode on Mojave. So it should be fixed for the next v4 beta. I was able to simplify the dialog level management quite a bit so hopefully it won't be likely to get broken again.