Finally, I had time to test it with linux 4.8.0-040800.201610022031 amd64 and with the 4.8.0-22 versions. In both cases the problem still exists. However, the content of the black rectangle has changed. It now includes the first line of the console frame buffer (in a slightly distorted way).
The bug #1611124 https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1611124 might be related, as I get the same error with W: Possible missing firmware /lib/firmware/i915/kbl_guc_ver9_14.bin for module i915 W: Possible missing firmware /lib/firmware/i915/bxt_guc_ver8_7.bin for module i915 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1628506 Title: Dual monitor - screen flashes and turns black on mouse movement and keyboard input To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1628506/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
