Accessed none trying to play sound on surface type

At the start of my ABP I initialize the BP and check if the player is valid etc, no problem there.

However when trying to play the footstep sounds depending on the surface type, I get accessed none error when closing PIE. The sounds still play however but only for the default surface type

Add an isValid node check for PhysMat from the hit result, before the setting of custom physMat variable after it.

No dice, I tried a few things with no luck so I just made a new system overriding the RecievedNotify function on an AnimNotify and avoided the AnimBP.

Main graph (RecievedNotify)


Function used to select sound based on player movement type

This system is however quite complex and I’ve not seen it done so extensively before, but I just need the sound to play based on the players, walking state and surface type. Any advice for this sort of setup?