Just chipping in a solution that worked for me. Even if the Zoneshapes are set up and the chevrons confirm they are linked, its still important to make sure that the state tree wander/navigation component is set up to query the corresponding tag assigned to the zoneshape.
If this isn’t matching I’ve found agents will navigate on the first one they are initially spawned on until they are required to assign a new wander/nav target and then cannot locate a valid location because of the missing tag.
Hope this helps anyone else who goes down this rabbit hole - or possibly me again in the future in which case - Hi Joe 
