Seems that a customer support call to Miele is needed. Can you pause the cycle, change the dryness level back to Normal, and resume the cycle? Or is the setting not allowed to be changed unless the cycle is fully canceled and started over (which presumably repeats the problem)?

Just for fun I would (a) thoroughly clean the lint and plinth filters, (b) disconnect and reconnect the dryer from/to power, (c) reset the Programmable Functions to "factory default" as described in the Operating Instructions.

All lint and plinth filters are routinely cleaned, not merely because we are diligent but because the machine reminds one to clear them. Halting and resetting the selection results in a repetition of the problem. I unplugged it and plugged it back in, verified that the unit is connected to the WiFi and all updates are current. One correction to the original post. The selection changes from 'Normal' to 'Machine Iron' rather than 'Hand Iron'. An earlier problem with this unit was when the selection was changing from 'Normal' to 'Hand Iron' which was apparently corrected with a system update administered by a repair tech.

Ah, you updated the software. I was going to suggest that -- since updates aren't automatic -- given that an earlier update had solve a previous malfunction.