I have no idea what's going on so I can't even give some "I've done A and B and C" to help get the process started...
The TL;DR is I can only connect to my primary hub using Remote Access BUT I can access my secondary via local access. No idea why. I guess I've tried a reboot and update, but that didn't do anything.
Secondarily, all of the devices that are shared via Mesh are showing as OFFLINE. I'm guess secondary hub can't talk to primary hub, therefore confusion.
Do you have a DHCP lease reservation set for the hub on your router?
Here is my suspicion. Other things could cause what you are seeing, but this seems to me a likely cause.
Your hub’s IP probably changed during a reboot after a firmware update, or during some other reboot. The IP can change if your hub simply gets its IP out of a general DHCP pool. For this reason, the general recommendation is to set up your DHCP server (usually on your router) to reserve a DHCP IP lease for your hub’s MAC address, so that, when your hub makes a request for an IP from the DHCP server, it gets the IP you reserved for its MAC address.
Now, your hub ”phones home” to Hubitat so that Hubitat can know the hub’s status, firmware, etc. If you go to my.Hubitat.com, your registered hubs will be shown, as well as their IP. It takes a while for this to be updated. See what the portal thinks are the IP addresses for your hubs, then try to access your primary hub using the local IP address shown on the portal for your primary hub.
Because the hub phones home with its current info, including IP, the Remote Admin can go back down that tunnel and contact the hub.
Try rebooting your secondary hub so it can rediscover other hubs sharing their mesh.
As stated above, likely your ip changed. Open a web browser on your local network and go to find.hubitat.com, if that doesn't work, download something like angry ip acanner and scan your network..
UPDATE: Short version is that I have some major router issues that I need to solve that I think will solve all of this. Right now things work 'well enough' to live with it.
There was a power outage and when things came back up they were 'wonky'. I use a Comcast modem and an Orbi router/satellites for wifi. I can't connect to the Orbi at all and when I thought I had (I'm pretty sure I was in for about 10 mins... ) the SSID was blank. But I still have wifi (and hard wired for that matter).
I think I should probably just reset the router to factory settings and redo the whole shebang but that would be a LOT of passwords to enter.