Skype on Ubuntu 18.04 issues - doesn't start and logs me out
Solution 1:
You probably aren't using the latest version of Skype. Try installing the Skype snap package with:
sudo snap install skype --classic
If that doesn't work try installing the latest version of Skype from the insider channel.
sudo snap install skype --classic --channel insider/stable
Solution 2:
This is a known issue with XWayland on Ubuntu 18.04.
It will be fixed with a future HWE update (packages linux-generic-hwe-18.04, xserver-xorg-hwe-18.04, xwayland-hwe-18.04). But it remains unclear when this will actually happen.