Hub Link has stopped updating virtual devices. Everything was working fine until around a week ago, so (as usual when stuff breaks) I was forced to update to see if there was some fix. Unfortunately, there was none.
Also, Alexa was reporting that devices weren't responding when issued commands (e.g. "Alexa turn on game lights." "Game Lights are not responding..." >>> Light turns on.) This issue was fixed after updating.
Also, Mode Manager has completely stopped working for me. I didn't notice this issue until after updating.
I experienced similar issues with the inbuilt Hub Link. It would seemingly randomly stop working, and would not be prompted to work again without re-installation. Instead of investigating that deeply, I chose to use the custom app HubConnect. I'm reluctant to 'pollute' my so called native hub with custom apps and drivers (I have a second hub for that), but I can report in this case HubConnect works very reliably and without fault.
So you have those two choices. Get with support and work it out (hopefully report your findings here) or try HubConnect.
The edits you added after my post, indicate a larger problem though. Mode manager not working specifically seems pretty worrisome.
What's the install entail? I've been lazy for the past year and trying to be hands-off. So hopefully it's copy-paste-config-->working.
I don't even troubleshoot anymore unless I damned well have to. (I left a Keen vent not functioning for 2 weeks, until temps hit over 100 and I had to dig in to find that the OEM batteries corroded the contacts.)
Unfortunately no. You'll need to install the app on both hubs, setup one to be the client the other the server. You'll have to install the generic HubConnect Drivers corresponding to the devices you wish to share to the client hub on both systems as well.
If you're not into tinkering, HA in it's current state is likely not a favored hobby for you. It requires constant maintenance.
Hob Link and OtherHub were created to assist with migrating from ST to Hubitat. They aimed at, successfully, assisting with moving devices and automations from ST to Hubitat.
HubConnect is a different tool in the sense that it's intended to work in a static config. Where the devices are in place and aren't going to move much at all. It's bidirectional and most critically, multi-hub focused. The initial uses of HubConnect were to connect 3 Hubitat hubs in an array. Then SmartThings was added to increase the array to 4 Hubs. Most recently Homebridge was rebuilt into a HubConnect version and a MakerAPI version. Thus there's an array of 5 hubs at the center of the basic idea of the tool. That does NOT mean you need 5 hubs!! Two is fine. One Hubitat, one SmartTings is ok too. One Hubitat and one Homebridge, also good.
The point is, installation instructions try to assist with the 3 hub architecture, with 5 being the same but bigger and 2 being the same but smaller. All of the above is why Doug says: "unfortunately no" -- it's going to take a chunk of time to do right.
Once it's installed and setup, the bulk of it's traffic will be attribute info. Obviously, during the build process it creates virtual devices.
Your Hubitat Hub is 'broadcasting' it's event stream 24x7. HubConnect gets installed to listen to the Event stream and for devices you've told it to listen for, it injects the Event into the local Hub.
It's probable that your simplified description is close enough... not for me, but perhaps for you, yep.
LOL...sry for the oversimplification, but thanks for that info. It looks like I'll have to sit down and actually think through the migration, instead of just running roughshod and picking up the pieces later.