Hi there. My understanding is that you want to block the Crouching input key if your character is swimming, correct? So, how are you setting your character’s swimming state? I mean, when your character detects a water volume, are you setting ‘movement mode = Swimming’ or only a boolean ‘Is Swimming’? Use the same variable in the branch node. Also, make sure inside your character BP, select Movement Component, open the details panel and verify if ‘can crouch’ and ‘can swim’ are correctly checked.
