Beta Guide first line goes blank

After a few hours my Fire TV 4K guide goes blank after about 8 hours on the first HDHR OTA channel 4 in Seattle. To recover, I have to force Channels DVR Beta to stop and relaunch. On relaunch it loads many days of good guide data, but after about 8 hours, the first channel guide contents goes blank again. Looks fine on mobile app, and on web, as well as on HDHR app. I submitted diagnostics.