xdm loops when trying to login

I've setup Alpine on my laptop, and everything works perfectly until I get to Xorg.

I ran setup-xorg-base and then tried to add xfce4.

alpine-desktop contains a lot more than what I really need at this point, so I figured I'd go piece by piece.

So I did apk add sudo xfce4 xf86-video-intel xf86-input-synaptics xdm adwaita-icon-theme and setup xdm and my ~/.xinitrc file (with exec startxfce4 as the only line).

But when I reboot and enter my username & password to the xdm login screen it just loops back to the login screen. I can login at the command line with my user. And at the command line I can run startxfce4 and that works. But I have no idea why it doesn't work from xdm?!

This is what my ~/.xsessions-errors file contains:

/usr/bin/startxfce4: X server already running on display :0
XDM authorization key matches an existing client!xfce4-session: Cannot open display: .
Type 'xfce4-session --help' for usage.

There's a whole bunch more in the .xfce4-session.verbose-log and the xdm.log but they are quite big. So if there's something specific to look for I'll post just the relevant parts - unless you need to see the whole thing to know what's going on?!

Thanks,