Ubuntu 17.10 Lock Screen causes reset

[Alex Davies]

Hello

Locking the screen causes the system to 'reset' - it does not restart as if you were to hit the restart button on the PC case, as it is not going back to the BIOS and boot bleep, rather that it slowly returns to the login screen and once you log in, you are presented with the 'first time' view of Ubuntu.

Effectively, if I lock the screen, all of my apps and open documents are being closed - improperly I believe, as it triggers the LibreOffice recovery process.

This problem is not found in the dual-boot Windows 10 installation on this same PC.

I suspect this may be tied to the video/graphics system, as it seems that this 'reset' is more likely the longer you leave it. Usually, an immediate lock then login won't trigger the problem, but if you leave it for ten minutes, it almost certainly will. I cannot consistently replicate this problem.

These are the system details:

Ubuntu 17.10
Memory: 7.8GB
Processor: AMD Althon ii x4 651K quad-core processor
Graphics: AMD Pitcairn
GNOME 3.26.2
OS: 64-bit
Disk 123.5GB

As for hardware:

It's an Athlon II 651K CPU, in an Asus F1A55MLE (F1A55-M LE ?) Motherboard, with 2x4GB RAM sticks, and a SanDisk SSD. Notably, there's an Asus 7850 GPU in there, and I suspect that this may be the problem - perhaps not playing nice with the Monitor (an iiyama B2888UHSU 4K 28-inch unit, connected via DisplayPort). There's also a TP-Link USB WiFi dongle in the back.

tl;dr - After locking the screen, the login window is slow to appear once you move the mouse or keyboard. Once you log in, it's like you are logging in for the first time. All the apps have closed. I suspect this is related to the monitor-GPU combo, but I can't consistently reproduce the problem. System works fine otherwise.