Here is I suppose primary ticket, as that one is already assigned.

In my custom Zeus mission, I removed all modules (Set Costs) linked to the Game Master module and synced only one the Set Costs (Side) module (All values set to 0) to the GM Module. Then I just entered the Zeus's unit name and after this, I'm able to see all empty buildings and even units and objects from Modes.

Problem persists even under version 1.66
I tried verify application files, official and my unofficial mission but nothing.

Me and my friend have the same problem but not only empty groups but all playable units mostly from modes.
I noticed of this bug after the update 1.64

I'm having same problem.