Possible your adjacent routers don't like the gratuitous ARPs issued by the new active member upon failover. In that case you either need to turn that protection off (ARP state tracking) on them, or set for VMAC mode on the cluster object. However if you do that, make sure all switchports the cluster members are plugged into are configured for portfast to set STP Listen/Learn timer to zero.
Attend my 60-minute "Be your Own TAC: Part Deux" Presentation
Exclusively at CPX 2025 Las Vegas Tuesday Feb 25th @ 1:00pm
