I noticed some bugs that can occur with some 3D objects and have listed a couple down below.
The solar panels both flat and angled do not have a rear texture. (These panels at EGVN are facing away from the taxiway presenting no panels and just framing)
The ATC top part of a tower does not have a floor, of which underside textures were added in 21.4.
This airport was EDDF.
Would be appreciated if this could be passed on to the correct places if they aren’t already known. I imagine the tower isn’t too important as the tower here would likely only be a temporary problem than an eternal one.