Why do stations I've scanned in, that show up on the OTA management screen get dropped off the guide after a period of time? I have an HR-21 and AM21. I live in between three TV markets. Chicago, Grand Rapids/Kalamazoo and South Bend. I have a large steer able OTA antenna with low noise amp on 40ft tower. I have gone thru the zip code search setup procedure many times to find the best combination of stations. 49022, 49101, 46409. I start by inputting the primary 49022 and secondary 49101, works great but missing Chicago. So I go back and enter 49022 again for primary and 46409 for Gary to get the Chicago stations. At this point all the stations I want show ALL up on the manage OTA channel page. I can unselect the few that I don’t receive or don’t want. The channels all show up in the guide and work properly but after a few hours or overnight the Grand rapids stations I entered first as secondarys disappear and the only secondarys in the guide are the second set (Chicago) that I entered in last. Weird thing is all the channels still show up on the OTA management page where you select which channels you want on the guide. I have all the Grand Rapids stations selected but they dont show up in the guide. Why do stations I’ve scanned in that show up on the OTA management screen get dropped off the guide after a period of time?