I am in the process of trying to debug a Version 3 install and having problems. As a check I put a successful prior install with a version 2 board. . I can connect to the Version 2 Board locomotive and ran a successful firmware upgrade. So I am connected properly. The engine responds to commands okay.
So I put the new install with a version 3 board on the track.
At first the new locomotive would show on the engine list. I went through the add cycle and the app responded that the engine was add and a temporary wifi connection was established. I then exited to the Main panel and could not see the new engine. I closed and restarted the app. The engine did not appear. So I recycled the app. I still did not see the engine but it was visible on add new locomotive. list and I ran through that again. It failed to add again not appearing on the main locomotive list. I tried it again. Each time adding the network password. This time it did not say successfully added and after recycling the app and clearing cache, it does not appear on the main screen or the add new locomotive scene.
I rechecked by running the good install and it comes up as it should. Is something in limbo. I recycled my router and tried again. The existing install works. I left it on the test track and put the new install loco back on the track too. I get a successful install for the new loco, but it does not show up on the main screen so I can complete setting it up. I tried recycling the app again and it does not show up. It show up on the add loco list again this time. This time I get a connect to network with temporary address. Again it does not show on loco list. once again it doesn't show up but is still on the Add Loco list. I seem to be in a loop. Note this is a diesel loco like the successful first.
I have an old Galaxy S8 somewhere in my tiny office/workbench layout room. I long ago took it of network. Will try to find it, remove SIM card and charge it up to see if that will work. May take a day or two will let you know result.