I have also tried a USB-C charging hub, and got device unrecognised errors which repeat every few seconds, and no charging. When I plugged a USB mouse and keyboard in (one time – have not tested since), the devices worked fine and the device unrecognised errors stopped. However, with any other devices (e.g. USB 3.0 HDD) connected through the hub, or even with no devices connected to the hub, the device unrecognised errors kept repeating.
I would be interested to hear if a USB 2.0 Micro USB OTG charging hub would work with a USB-C to Micro USB adapter, though it sounds like that has been tried (at least with a super-cheap Chinese one) and didn’t work.
I’d also be interested to hear if back-power would work through a USB 2.0 hub, as someone on the Chuwi forum noted they had success with this with a powered hub (read post from noggin: http://forum.chuwi.com/thread-133-2-1.html). It’s worth noting they said it was a powered hub, so maybe a normal OTG charging hub doesn’t work where a proper powered hub might.
At this point, every attempt I’ve read of anyone trying to use a USB 3.0 hub seems to fail. Other USB 3.0 devices connected directly (with a Type-C to Type-A adapter or not) sound like they work fine, but not USB 3.0 hubs. I suggest people focus on USB 2.0 hubs only for OTG with passthrough or back-power charging. Regardless of whether or not it’s right that these tablets shipped without USB working properly, let’s find a solution that works.
