Found the problem in mutter:
CLUTTER_FEATURE_SWAP_EVENTS is missing because
COGL_WINSYS_FEATURE_SWAP_BUFFERS_EVENT is missing because
cogl-winsys-glx isn't being used because
xorg 2:1.20.4-1ubuntu1 is missing/has broken GLX support...
$ glxinfo
name of display: :4
Error: couldn't find RGB GLX visual or fbconfig
Found the problem in mutter: FEATURE_ SWAP_EVENTS is missing because FEATURE_ SWAP_BUFFERS_ EVENT is missing because
CLUTTER_
COGL_WINSYS_
cogl-winsys-glx isn't being used because
xorg 2:1.20.4-1ubuntu1 is missing/has broken GLX support...
$ glxinfo
name of display: :4
Error: couldn't find RGB GLX visual or fbconfig