Did you set the AI character to auto possess when spawned or placed in the world? That worked for me. Because otherwise your Character won’t be possessed by your controller making it do nothing. Also make sure you have an NavMeshBoundsVolume.
SpawnAIFrom clss would have been an option if you were using a behaviour tree. The bug that caused actor spawned from class not to work with AI is fixed. Just make sure the possession is right. Also spawn actor from class lets you expose variables at spawn 