This usually happens after an update, or just moving the Surface Book.
The last time it happened, until today, I was in the middle of a video conference and got the 'disconnect, reconnect' noises all the time - keyboard and mouse didn't work. Reconnecting the power to the hub that usually has an effect produced nothing, disconnecting and reconnecting to the Book had no effect. In the end cleaning the contacts to the Book with Isopropyl Alcohol seemed to do the trick and it ran without issue until Patch Tuesday - after installing the updates (today) with the usual keeping a bottle of brandy close and hoping for the best.
This time it restarted OK, but then started to throw the toys around again with mouse and keyboard disconnect.
Another problem that happened regularly in the past was the screen resolutions messing up and constant reboots before getting them back to normal (right clicking into screen settings only produced a menu with basic resolutions that would have been sad in 1990)
I do believe that my hub is a series one (although the problem seems to exist with both) and I have not updated the firmware for a while as the there are lots of reports that firmware updates will brick the hub
It's life Jim...