Thanks for the responses, guys. I really appreciate it, as I'm now kind of surprised/alarmed that apparently no one around here has seen or experienced this...
Yeah, I've already done all the usual network troubleshooting. I have restarted all the TiVos, the cable modem, the router....everything. I'm increasingly convinced that this is something on TiVo's end....that the TiVo service is blocking my whole account somehow. If it were a broader service outtage, now into its second week, there would be a lot
of verbiage about it here.
I've checked my router logs and there's nothing being blocked on my end, and there have been no internet issues on any of our other devices. All the TiVos (currently five units....Roamio Pro, Premiere XL, Premiere, Mini, and an S3, all with Lifetime service) exhibit the exact
same behavior: they continue to make successful GC, VCM connections, but their last successful service connection was on April 14 (April 13th for the S3). They are all hard-wired, and are running varying software versions. Only the Roamio is updated to 20.4.7. They all pass their port configuration and DNS resolution tests. Again, to be clear, they can and do connect to the internet....I just watched a Netflix show on the Roamio last night, and I can successfully log on from the other units as well.
I'm about to do one last troubleshooting step before calling TiVo. I'll try connecting a couple of them directly to my modem, bypassing the router completely. I've little expectation that it'll make any difference, but at least I won't have to do it over the phone with a CSR.
And suggestions or thoughts...even speculation!...is welcome at this point.