gdm3 greeter missing characters

[Andreas Enström]

The greeter is missing some of the text characters in the words, but only when not logged in.
If I login and lock the desktop, everything looks fine on the lock-screen.

I'm on a laptop with a nvidia optimus 620m using nouveau drivers, for some reason my unplugged vga connector is detected as a display. If I mouse the mouse over to that invisible screen, it sometimes seems to crash the greeter. But it restarts within a couple of seconds, so I can still login to a session.

If I understand things correctly the greeter is running on wayland?
I'm speculating that this seconds monitor might be the reason wayland sessions are not working correctly for me after a fresh install. It freezes directly after login. First I have to use an xorg session and remove the desktop icocs, then I can login to wayland, change to single display and turn on the desktop icons again.

I'm just speculating here, but since the greeter sees two monitors, maybe that could have something to do with the problem?

By booting with "nomodeset" everything looks as it should and I can't move the mouse over to the unconnected second monitor (guessing, the greeter does not detect it anymore).

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gdm3 3.28.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15
Uname: Linux 4.15.0-15-generic x86_64
ApportVersion: 2.20.9-0ubuntu5
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 19 13:26:21 2018
InstallationDate: Installed on 2018-04-19 (0 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180418)
SourcePackage: gdm3
UpgradeStatus: No upgrade log present (probably fresh install)