After IOS XE switch upgrade from 3.6.x to 16.9.x I lost port-channel configuration. While trying to apply it back on to the interface I got this error Command rejected: conflicts with IPv6 Snooping (FHS). This can be a potentially dangerous situation if the upgrade was done on the remote switch first.
After investigation, it appeared the following interface command was causing the issue ip device tracking maximum 10. In IOS XE 3.6.x it was working just fine.
I’ve removed this command and reapplied the port-channel config to restore connectivity.