I have a HDHR3-US and HDHR-EXTEND. When using the channel guide on either iOS or tvOS, channels which appear under “HD Channels” on the EXTEND will NOT be listed under “HD Channels” on the HDHR3-US. In fact NO channels appear under the “HD Channels”
This is a known issue with the older model hdhomeruns. They cannot detect if a channel is HD or not.