Just as a data point, I am running the latest TestFlight (11.6.2052) on two AppleTV 4Kâs, and am not experiencing this issue as youâve described it.
One AppleTV is controlled by a Harmony 650 (infrared only) and the other is controlled by a Harmony Companion (set up as a Bluetooth keyboard.) I am able to manually enter channel commands with both of them, as I have been able to since the start, and it works to change the channel I am watching in Channels.
I havenât changed any of the configuration, havenât removed or re-added any part of it, and it all still works.
I have never been able to manually enter channel numbers when in the guide, though. I tried it a long time ago, and it didnât work then, and I didnât know that it had ever started working, so Iâve never missed it. Iâve only changed channels this way whilst watching live TV.
That said, I did read elsewhere that there is a newer entry for AppleTVs in Harmonyâs database, called âHarmony Pro BT Apple TV 5.â And with this newer entry, there are now true REW and FF buttons. (No more press and hold to get REW and FF. The left and right direction buttons still work as before, so pressing them will skip back and forward, respectively.)
Iâm still using the older entry, and it works fine for my needs, so I wonât be changing anything soon. But I mention it in case that newer entry, or some other one, is whatâs caused your issue.
What specific settings did you choose when configuring the Harmony to control the AppleTV?