Thanks. Just off the phone with Denon support as they did not respond to my online tech support request, they suggested to try a reset, and if that doesn’t work, to return for a replacement.
Here ya go. Do theses in order. Try each level of reset twice before moving to the next level.
Copied and pasted from AVS Forums:
“How do I reset the microprocessor or do a network reset?
When the AVR is acting up or doing something strange, try the following steps before resorting to a microprocessor reset:
1. "Restart" - set the AVR to Standby and press/hold the power ON button until "Restart" is displayed on the front panel.
If no joy, then ...
2. Soft reset - set the AVR to Standby and unplug the power cord for about 10 minutes, then plug back in the power cord and turn ON.
If neither of the above resolves the issue, then you'll need to either do a network reset (if network related) or a microprocessor reset. You'll also want to reset the microprocessor before doing anything else if you purchased the AVR as an "open box" or demo/used/refurb unit to ensure all settings are returned to their original factory defaults. Prior to doing a reset, you can SAVE the config file to a USB thumb drive so it can be LOADed after doing the reset (SETUP - GENERAL - SAVE&LOAD).
Network Reset (“Amp Assign”, “Speaker Config.” and “Video” settings are not reset)
1 - Turn ON the power using ON/STANDBY.
2 - Select the HEOS Music source
3 - Simultaneously press/hold the "DIMMER" and ">" buttons for at least 3 seconds.
4 - Release your fingers when "Network Reset" is displayed on the front panel.
5 - "Complete" will display when the reset has completed.
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Microprocessor Reset (aka "Reset to original factory settings")
- Note: In some cases, where one microprocessor reset did not resolve an issue, doing at least 5 in a row did.
1 - Turn off the power using ON/STANDBY.
2 - Press and release ON/STANDBY (as you normally would when powering on the AVR) while simultaneously pressing/holding the "INFO" and "BACK" buttons on the front panel
3 - Remove your fingers from the two buttons when "Initialized" appears on the front panel display.
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Factory Restore
1 - Turn off the power using ON/STANDBY.
2 - Simultaneously press/hold the: "SETUP" and "DIMMER" buttons on the front panel and then press the ON/STANDBY button on the front panel. This procedure will take 15-20 minutes to restore to the original factory firmware.
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** NOTES:
(1) Prior to resetting the microprocessor, you can SAVE the config/settings (to include Audyssey settings) to a USB thumb drive using the SETUP - GENERAL - SAVE & LOAD setting.
‘Here is the direct link to the site and Thread: (Worth reading the first several pages):
https://www.avsforum.com/threads/the-official-denon-avr-x8500h-13-2ch-flagship-avr-thread.2952552/