I am encountering a similar issue. Attempting to upgrade from R80.20.50 to 81.10 on a 1570R HA Cluster. The cluster is managed by SmartProvisioning on R81.10
Steps I took -
1. upgrade to 81.10 using the Quantum Spark 1570R Appliance Upgrade Wizard on gateway A
2. upgrade to 81.10 using the Quantum Spark 1570R Appliance Upgrade Wizard on gateway B
3. pushed policy from SmartProvisioning -- process failed
4. updated the Version of the device A and B in the SmartProvisioning Edit Gateway... screen from 80.20 to 81.10
5. after clicking OK the changes would not save
6. eventually the failsafe logic in the upgrade steps reverted each device back to 80.20 bc I was never able to push policy to either device in the cluster.
My plan now is to delete the cluster object and then upgrade the devices, then add a new cluster with the 81.10 profile.