Following up my original post in case anyone else runs into this problem. I fixed my problem by going into the BP_Water blueprint in the Instant Swimmable Water marketplace asset and disconnecting two nodes:
In the WaterOverlapBlueprint section I disconnected the “Set Physics Asset” from the On Overlap Event and I disconnected the “Set Physics Asset” node in the End Overlap Event chain of logic.
They were set to a different physics asset than my main character and it was causing problems. If you need ragdoll physics underwater you can pick the correct asset or configure a workaround if you are using multiple physics assets.
Good luck!