Marantz 5013 loses sound at the same time each day

Hi All, After a few years, I finally realized that this reciever drops sound at the same times each day for about 5 seconds. ALWAYS at 7:44PM (Mountain) and I think it does it every 2 hours. I don't usually watch TV at other times so can't be positive, but 7:44PM like clockwork. I'm using ARC to a Sony TV. I've sent it in for service (like 18 months ago) and they updated everything, checked it, etc but could not replicate the problem. (I didn't know at the time that it was at the same times each day). The other data point is that the optical output from the TV does NOT have the problem as I can hear the speaker sound drop but my headphones that use the optical play right thru. I'm of course out of warranty now so hoping for some solution from the experts on here. I tried to turn of updates thinking perhaps that's when it was dropping but not sure I did that correctly. Any ideas would be appreciated!

Thanx!