I see. Well, if possible, I’d try it without the hub. At a minimum it will help you eliminate the potential fault for one of the 3 involved components.
I’d make sure that the app is up to date with the latest version and try to get the android device running on minimum resources then see what happens with the direct cable.
You may want to check out the dedicated Koala thread for additional info or similar issues, it’s a pretty active topic here so there’s a lot to go through but you can use the box under the search bar that says “search this topic” and narrow the results to the thread you’re in, and that may help a little.
Hopefully you can get this up and running quickly enough.