Yes, a workaround. Basically, for some reason it is just flagging oversize units in the shipment. Once I remove all the oversize units and it is just a shipment of standard size units it seems to process without issue. It has nothing to do with the dangerous goods it seems but is instead mixing standard and oversize units.
"No fulfillment centers are currently available to receive the total quantity of dangerous goods units in this shipment"
Well I’m glad you were able to get to a workaround at least!
Hopefully the bug gets corrected soon.