continuing this closed thread because this is still an issue and has been for years.
to the OP - i posted a thread with video evidence of this years ago and was torn apart by the "community helpers" and channels devs that there was no issue. it's still an issue with OTA, at least on apple tv 4k 3rd gen. you can literally side by side hdhomerun player and channels and watch channels start to have this issue.
check my post history, it was pretty funny and made me realize channels will probably never be loved like it should be by these devs. they should get their llms on it 