Thank you for your response. That is not what I am experiencing. I have never seen this scenario before. The DCC Knob and Cab Mode Engine Controls have collapsed and all that is displayed in the lower right corner are the row of buttons for coupling and decoupling, horn, and sanding and that small arrow you mentioned that toggles the visibility of these buttons.
Neither AI or manual control is functional for more than a few seconds and then it is as if something is taking control and the Train simply stalls or is waiting for clearance. I do not have access to "message history" to see what AI is reporting, which is not helpful. The button for Message History is absent along with DCC and Engine Controls.
I have completely uninstalled Trainz and reinstalled everything, which maybe my mistake was in saving the offending route and session and reinstalling that. But this is a route that I have spent two weeks and long hours replacing missing track that was a Missing Asset from a download on the Download Station for a map that I have wanted for years.
Granted, I can trash the whole thing and do it all over again, it's not as if I haven't already spent years nursing Trainz along after investing in it only to be disappointed time after time after time because of constant encounters with Missing Assets after Missing Assets. I would be more open to doing this again if I knew what caused this to begin with. Will it happen again, probably, how do I fix it without having to do it all over again. And I pay a subscription for this privilege.
This link shows the collapsed state of the HUD Panel with the row of buttons. The DCC Button and three dots for toggling Cab Control are gone.
https://ibb.co/qFdsdwCq (The popup text informs me that the "Arrow" should Toggle the panel for train control, but it does not do that thanks to whatever I did with my tremor.)
I am ready to trash Trainz and call my venture into this %^&*&&*$ nightmare a lost effort.