As much as you come across here Barry I'm not sure you'll remember but.......
I have a 2 loop layout with each being powered separately by each handle of a Z4000. I was having an issue where any MTH engine would not be read by phone or tablet (was getting the timed out error) if both sides were powered up simultaneously. I had no problems when only one loop was powered up providing the engine I wanted was on that powered section. You had me check some things out with wiring and all was good plus we knew that all worked well with the DCS remote. Then you mentioned the wifi unit but that got put on the back burner. And then this happened.....
I finally got around to updating the DCS Wifi firmware to 1.1 tonight and everyone is much happier again in train land.
BTW when the problem existed I was able to power up the second Z4000 handle after an engine was started up and continue to run without issue. Hope this helps with anyone else that might have a similar problem in the future.
Thanks again!