I will set up a more complex network environment to reproduce what you said. I guess these problems are caused by a large number of data transmission between panels. Although I have found some problems and have fixed them, there may still be problems I haven’t found.
Also could you describe the connection setup. I recall something about separate buildings, so just how far is that. Also you mentioned potentially there is interference from the nearby radio transmitter, do you have the T3 controller mounted in a metal can to protect against that. Any little thing may help.
You confirm that you have connected the ground for all power supplies and controllers at the various cabinets to earth.
[June 16 Update] Ted reported by email that a metal can improved the communications significantly.