I can confirm this bug too. Using MSI GS 73 with Ubuntu 18.04.2 + latest official kubuntu desktop. The notebook has 4k display and I'm using external dispaly LG 27UL850-W, which is 4k too.
As it was mentioned in the thread, it seems to be related to the "Screen energy saving" checkbox in the "Power managment settings". Once the timeout for this option passes both displays goes to power saving mode and becomes blank black. After you resume a session by moving a mouse, you can actually notice, how all windows first goes to the laptop display, then, all windows moves to external display. This is a MAJOR usability bug. Need to manually re-position all windows again and again. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1573345 Title: Dual monitor loses settings after screen sleep To manage notifications about this bug go to: https://bugs.launchpad.net/kscreen/+bug/1573345/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
