I lately observe that the content is often many days(!) out-of-date ... until I log in...

I don't know if the problem is on your end, or somewhere in between, but it's not on our end, because PM doesn't cache any output. (There are a few pages which are "cached", such as Selected Best Nodes, but you don't seem to be talking about any of those.)

If you would like to take some screen shots the next time you see it happen, and send them to me, I'd be happy to take a look.