major issues with Canon B4 lenses attached to Ursa Broadcast

Having major issues with Canon B4 (digital) lenses attached to Ursa Broadcast G2 camera's.
All the lenses are stuttering on the focus even when no focus demand is connected.
Running the latest firmware on body, fiberback and basestation.
Troubles started to occor after updating firmware. Any suggestions?

We run our Ursa Broadcast G2s with the likes of the Canon CJ25ex7.6B UHD lenses without issue.

I can't assist more, but further information might help others answer:

Which model lens(es) exhibits the problem?
Have you tried other manufacturer lenses i.e. Fujinon to see if the problem still occurs?
Does the problem still occur when all the fibre kit is disconnected?
Are you using BM demands via USB-C or Canon ones?
Does the lens have the facility to reset or update it's firmware?

Does this also occur when not starting the Atem Software Control? I got problems with iris with my Ursa broadcast G2 and downgraded ASC to version 9.3.1 and that solved the problem.
If your problem is not ASC then you can downgrade the firmware of your camera’s. I almost never uograde because lot’s of upgrades gave me problems.