How to set NavMesh to correctly form around enemy character

Does anyone have any suggestions?

I’m trying to get my NavMesh to correctly set around the enemy character - when I put my enemy on my level, the NavMesh adds a little non-navigable ‘island’ around it. This island prevents the enemy from moving anywhere.

I can prevent this if I place the enemy above the level; it just falls onto the ground and starts pathfinding normally - it’s a useable workaround but I’d prefer to find a more elegant solution.

Any suggestions would be greatly appreciated!