I have and HR54 and HR21 and both have an AM21 connected. They are connected via SWM and I’m using a diplexer to combine my roof antenna with the satellite signal. Behind each receiver I then use another diplexer to split it back out. I live in northeast PA and the AM21 does tune in most my local channels. Just recently the AM21 attached to my HR21 died and wasn’t recognized. I was able to find a used one and replaced it. When I connected it and scanned for channels it picked 22.2, 22.3, 22.4 and 28.2, 28.3, 28.4 , which I’ve never been able to see in the guide previously. The guide also showed the programming for each channel. The signal strength for them were all around 95%, matching the base 22.1 and 28.1 channels I've always had. Since my HR54 is my main receiver I use I tried rescanning with all different zip codes , powering it off and on twice within 15 minutes to clear the guide and it still didn’t tune in the additional channels I even removed the AM21, rebooted so the device wasn’t found, then plugged it in so it was found as a new tuner, and did the setup with no luck. So thinking the tuner on the new AM21 I just got was better I swapped them hoping my HR54 would get the additional channels. Now both receivers don’t show the channels. I tried everything I read on the forums to clear the guide and retune the channels with no luck. The forums seem to point to the database not having the channels, but they have to be there if they showed up on my HR21 with the correct programming in the guide. So does anyone have a clue as to why this is happening?