Dealer looked at the radio today. Feedback as follows:
They were able to replicate the problem
Did a dealer only "hard reset" on the radio
Confirmed that I'm running the most up to date version number. Opened a STAR case -- STAR said they are aware of the issue and said that they are working on an update that should be "available next quarter". Did not recommend a radio replacement.
Said that "power cycling" the radio power button - i.e. pressing it twice, should reset the dimmer settings between the radio and display to get it to work again as a short term fix.
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Based on the forum feedback it sounds like I shouldn't hold my breath on the software update front. The pressing the power button twice on the radio has never worked for me before so I find that feedback curious. Hopefully, the hard reset will solve the problem for at least a little while.
Sounds like I should be escalating with STAR for a radio replacement.