My TCL Roku TV does the same thing. I thought maybe something happened to the TV tuner inside the electronics, so I went out and bought another TCL Roku TV and brought it home and set it up.
Everything on the new one worked (including the changing of antenna channels) at least *until* I let the TV do the software update. Please understand that this was a fairly controlled test with a brand new TV right out of the box. I set it up without an internet connection and went straight to the OTA channels. I ran it this way for about an hour.
Then I rebooted the TV with the factory reset, and let it go through a normal new user configuration (including entering my Roku account, etc.) and it also during this process downloaded and updated the firmware and all other software updates.
Once this was done, the OTA channels on the antenna will only work when you first turn on the TV and you can get to your first channel. After this, you can no longer change channels. The 5-way button for going to the chanel guide and moving up or down channels no longer functions (unless you hit the Home button, then it will work to navigate all other apps.
The only way I found to change channels on the antenna is to unplug the Roku TV from the AC outlet for 15 seconds and then plug it back in. This apparently resets the software and when you select the Antenna Icon you will be able to navigate to any channel you wish. Once you select that channel to view it, the software prevents you from changing channels again. Just like the video posted in one of the above posts, the night light flashes like it receives the signal from the remote, but nothing happens.
To take this one step further, I bought 2 additional remotes that I keep in the cabinet because family members have a habit of losing them around the house so I keep spares until the lost one shows up again. For this test I took out all 3 remotes and the all perform the same, so it is not the remote.
Definitely related to the most recent software update. When the stock Icons changed, so did the ability to use the antenna.
BKM