Mackie Onyx, Firewire not working after Ubuntu upgrade

I have a Mackie Onyx 1220 with Firewire card that I previously had working well on Ubuntu 18.4, Ardour 6.2 (I think), no JACK. I now have Ubuntu 20.04, Ardour 6.9. The Fire wire inputs to Ardour seem to work fine, but I cannot get the two output channels back to the board to work at all. I have tried every routing combo I can think of, with no luck. Any help is greatly appreciated. Thanks.