Volume on remote goes up and down when changing channels

Did you always have this issue?

In rare instances infrared remote codes can appear similar to different devices, so perhaps your Denon is responding to its volume commands when it shouldn't be. 

No, it started randomly. I've had the Denon receiver for two years.

Hi, @Tonyh. We're sorry you're having remote control issues. We have some solutions here that may help: https://www.directv.com/support/article/000092831 We're also sending you a DM to assist you further with your concern. Ariane, DIRECTV Community Specialist

I had exact same issue with my DirecTV Genie Mini.  We think it was an issue with the new HDMI-CEC update made recently with DirecTV.  Had it replaced with the Gemini box (C71KW-400) and problem went away.  

FYI.  If you’re wanting to use the Gemini as a wireless client to work with a main DirecTV Genie (HR55 or Genie 2), during set up, must go to main Genie and add new client through Whole Home, then factory reset Gemini for it to detect your main Genie.  

You need a WVB with the HR54.

Yes indeed. 

I had this exact same issue. I did a hard reset on my main unit and it went back to normal. 

I originally tried factory resetting the Mini Genie as well.  Did not work for me.  

I didn’t factory reset it. I simply unplugged the power cable from the DVR unit and plugged it back in. It booted back up and everything was back to normal.

I did that as well before factory reset.   Nothing worked for me, other than replacing the unit.  Glad it worked for you.

Welp, the problem eventually came back for me so the hard reboot was just a temporary fix.