@aaiyar Sir, please accept my apology. I am in no way trying to be difficult or insult anyone. I am sorry if my message came across as aggressive. That is in no way my intent.
I am, however, a bit frustrated because of my situation and that may have come through in my message in the wrong manner. I started having the Severe hub CPU issue early in this year (February or March). Out of frustration, I started this thread in early July. So it has been over a month of diagnosing and over 6 months of issues with no end in sight. I just want my little system to work.
I realize that most of the people on this forum, likely including you, are in no way paid for their time. So I am very appreciative of all the replies that I have received. Please accept my apology.
Nothing stands out as wrong... so I'd say set it up for a nightly reboot to deal with symptoms for now. I had a chance to observe the hub in its "high load" state, and busy bits happened to be in an OS process, which our support tools have limited access to. My best guess is it's trying to use swap space, the symptoms match. But there doesn't seem to be enough going on otherwise to trigger swap. In a nutshell, I don't have a root cause yet. However, a band-aid solution may work just as well, and there's a hub rebooter community app that makes reboot setup a breeze.
Just thought I would bring this to a conclusion. I installed the community app that gopher.ny referenced to reboot the C4 each night. I first tried to have it just restart each night but that failed and I had to have it reboot it each night. That seemed like such a huge bandaid fix that I decided to buy a C7. I removed and then installed all my devices on the C7 and have not had an issue yet.
Let's hope it stays that way.
(anybody want a C4?)
