System reboots upon resume from suspend

I have been using EOS for a while now. On one of my machines, recently (after some update, I cannot tell exactly which one) the machine exhibits strange behaviour. It will actually reboot after resuming from suspend. This is a big headache for me, I have already lost some work. It goes into suspend fine. But when I pull it out of suspend (either with keyboard, or pressing the blinking power button on the desktop), it will just reboot.

Also one strange thing: in the cases that it does come out of suspend OK, it seems as if something presses the F1 key during this resume, because there is always a dialog asking “do you want to reach the XFCE documentation?” which usually comes by pressing the F1 key.

Any ideas? Thanks in advance.

Take a look at the journal entries. The journal may tell you what triggered the reboot.