Iphone 7 buffering on WiFi

I have three Apple TVs and an iphone 7.
I NEVER have any buffering issues with the AppleTVs.

In the mornings, however, I like to watch the local news (OTA channels) while getting ready on the iphone7.

It buffers quite a bit (some mornings worse than others). I thought it was the channel (OTA), but tried a different channel with the same result. I thought it was the WiFi signal strength or the antenna, but have no issues when using the HD HOMERUN App for the same channel.

Perhaps it's just the fact that the iphone 7 is an old phone.
Any other suggestions or settings I should try to adjust?

Thanks.