Bad Z-wave link between house and garage

Between my house and my garage ( attached ) I have a concrete wall + steel siding in the garage. I get 9.6kbps speed for Z wave devices in garage, so it doesn't work well. I have a device inside my house ( Zooz Zen27 ) that is at 5' from one in the garage ( Zooz Zen21 ), so very close, but the concret wall in between (also have a Zooz Zen16 relais in garage) . My hubitat is centered in my house, with a line of sight of the garage wall. I'm thinking of adding another Hub in my garage. Does two hubs Hubitat work ok together ? Any other way to get a good link ? Thanks

If you have a WIFI AP, or wired even better, in your garage that you can connect your second hub to, then with the new hub mesh the devices on your second hub will be easy to control between hubs. There is also Hubconnect, but for just a few devices Hub mesh will be much easier to setup.

I do this with an attached work shop that is about 250ft behind my house. I currently have three HE hubs and a ST hub connected together.

A second Hub would be wired, for sure !!! Thanks.