On my instance, I had to update the xorg file to make it work, based on this:
https://github.com/jitsi/jibri/commit/74af3d71f207f5de301ecfea54649854ecd5880c#diff-0ac8721d266f43634213ca1b1995f895c0d892ca413b28164853790a60d1e2deR112