I recently installed Cisco Prime Infrastructure 3.5 so as to manage catalyst 2k, 9200 and 9500 then upgrade to Prime Infrastructure 3.6 to support 9500 switches.
It appears that Catalyst 2k and Catalyst 9200 are managed correctly and 9500 is shown as "Unsupported Cisco Device".
The part number of the Catalyst 9500 is : C9500-48Y4C
The 9500 ICMP and SNMP reachability are OK.
From the Cisco Prime Infrastructure Device Supported document find here, it seems that this hardware is supported.
Does anyone hit this behaviour ? I don't find any bug document about it.