I think we have the same issue!!!
It does look like underextrusion, but also the nozzle is hitting those bumps. Increasing extrusion ratio only makes it worse, not better.
I noticed this ~10 days ago or so and have been troubleshooting it since then, so not sure it’s connected to the firmware, I believe that came after, but maybe I’m wrong.
P.S. Anybody now when the 01.06.05.00 firmware came out?