I've been running ubuntu with gnome on my lenovo yoga 720 for about 6 months now. never had any issues until yesterday.I have been using a USB-C dongle that has 2 Displays connected to it with HDMI cables. Everything works if i start the computer without the dongle connected and then connect the dongle. I can use both screens plus the built in laptop screen BUT when i lock the computer or when it goes to sleep it will not recover from sleep. The screen stays black, no backlight and the keyboard is not working (lights vor capslock) the only thing that i can do then is hold down the power button until it goes off and restart the machine. When i then restart the machine it often starts without the wifi working. If i try to shut down the machine then, often it crashes again.
I tried installing Plasma KDE with the ssdm because i thought maybe it's a display manager issue but the problem is still there..
Anyone know what could be causing this?