Panoramic Modem Stability

For the past two Fridays I have had to fight with my internet connection from cox. I have the Panoramic wifi modem and the gigablast service. Last Friday the modem started flashing amber mid evening (9 pm). All front end connections over wifi and wire stayed connected but no internet access. Tried recycling modem, unplugging replugging cables and power. Engaged tech support. No one could get the modem talking to the internet. scheduled a service call for following Monday (3 day wait). Meanwhile, swapped out an older cable modem - still no internet. Then put the original Panoramic back and it just started working. Cancelled service call worked great until this Friday afternoon (4 pm) then the same thing happened. Cox couldn't get it working. Tech scheduled for Tuesday this time (4 day wait). Did the same test with backup modem but this time I checked signal and it looked like that modem was getting cox but maybe not registered as a client anymore. Anyway put all get back and panoramic working again last night and today. Gonna keep appointment this time but has anyone seen this where leaving the modem unplugged for like 30 minutes can fix a problem that a 30 second unplug won't? Caching issue (on cox side)? Overheated hardware (that only trips once a week or so? Modem possessed? (JK but you know those gremlins are pretty clever..lol). Thanks.