I upgraded my Xenial test system to linux-virtual-hwe-16.04-edge and with that it is working fine.
So we have a good testcase (thanks Rolando) a crash dmesg on the issue and confirmed that it is solved in a newer kernel.
Comes down to bisecting maybe, but there is a chance the kernel team just knows.
That said I'm rerouting the bug to the kernel Team.
I upgraded my Xenial test system to linux-virtual- hwe-16. 04-edge and with that it is working fine.
So we have a good testcase (thanks Rolando) a crash dmesg on the issue and confirmed that it is solved in a newer kernel.
Comes down to bisecting maybe, but there is a chance the kernel team just knows.
That said I'm rerouting the bug to the kernel Team.