Hi again Guys,
many thanks for the suggestions.
I have done exactly what you said and the goods news is that the player is no longer getting stuck and the controllers now cycle through their settings correctly which is fantastic! However, neither the player nor any of the other movable objects either seem to be affected by the water physics volume settings at all, unfortunately.
It is possible that I have missed out on something stupid, but I have double-checked everything in a regular template and the physics volume works fine there, so I am not too sure exactly what the problem could be time…
Once again any help at all would be very much appreciated, thank you!!