Device Serial/Hardware doesn't update when device hardware changes due to stale data in entPhysical table

We have routers that get upgraded on occasion, ME3400 to ASR920 for example. When they get swapped out, observium properly detects most things: interfaces, OS as iosxe instead of ios, etc.

However, the hardware and serial number and a few other things are not properly being re-detected. Even if you null those values from the devices table, the old values go back in. It appears to be something related to the data in the entPhysical table. The old values show there with a timestamp in the 'deleted' column, but there must be a sql query somewhere that's not looking at the deleted column.

If I purge the deleted items out of entPhysical for said device, it will appear correct upon next poll.