wd-15 xps13 ubuntu 16.04 troubles kernel 4.4.0-124

Hi folks,

I'm an XPS linux user with a WD-15 dock. I've been using this set happily for a few months since buying the dock from Dell. Having had a kernel upgrade to 4.4.0-124 in May I'm now finding that the dock unit is only partially working - I can no longer charge from its thunderbolt or drive an external monitor from it. It does provide Ethernet and USB connectivity ok though.

Anybody have any insight into this ? I'm guessing some upgrade has stopped this thing up from the laptop end.