we have core switches with PID : C9500-24Y4C and the current version is 17.03.04 , PID: C9200-24P with module C9200-NM-4X and the current version of C9200 is 17.03.04b
once I connect the uplink between the C9500 & C9200 using the 10G-SR the C9200 is not reachabe and not appearing at show cdp neighbor, the link is up & working fine on 1G
Note : I tested with another switches & fiber and it's same status
I had exactly the same issue with the same products.
Had to downgrade to 16.12 to fix this.
Seems to be a compatibility issue between NM-4X & IOS-XE 17.4.3 on the 9200 platform.