found a bug with spines I think. When I spawn a monster from a trigger.. they do not follow the path. In fact they spawn at the edge of the map, the corner were the PC spawns...spent sometime trying to debug then gave up...
Unfortunately, I currently can't look into this because I'm not on a computer that can open the editor, and I've never spawned characters from a trigger. It sounds like the first thing to work out would be how to spawn the monster where you want them to spawn because that sounds like a separate issue. You could try asking about that in the general modding section. Other than that make sure the monster being spawned has the GEN_SplinePatrol script and that it's configured correctly with the Spline's GUID.
What did you do to make the monster follow the path?
You need to add the GEN_SplinePatrol script to the monster with the GUID of the spline. The last three images in the tutorial explain how to do that.