Discovered as different hardware despite being identical

pebcakproblemsolver

I ran a discovery of my network and the NPM picked up on our switches at our remote locations.

However, it correctly read 2 of them as HPs and read the rest as unknown.

These switches are identical.
Any idea what would cause this?
Also, I should note that the corporate office also read as unknown.

d09h

Does SNMP work on all of them?  Can you list resources on all of them?  If SNMP connectivity was not successful, you may have only had ICMP discovery of the 'unknown' switches.