I assume you have verified the battery voltage is in normal range.
While I do not have the engineering/technical training to offer repair advice...Plz allow me to ask about & comment on: (for educational puposes)..."turn it back on, & turn on the stop switch" ("kill switch"?)..."hear the clunking of the DCT trying to return to neutral"...and "Turn the bike off, and back on, in the DCT returns to neutral".Took the bike out - per usual, started - it was in neutral - pushed "D" and that registered on the display.
Selected "M" and the "D" on the display disappeared.
As soon as I started rolling, however; the "1" gear indicator became "--" and no response to any DCT function.
When I rolled to a stop [this is the other peculiar aspect of this anomalous behavior] it clunks, shifting to 2nd.
Turn the bike off, and back on, in the DCT returns to neutral.