Then you simply have to add a action to the event where you stop your character: change animation sequence to stopped.
That solution may lead to some overrridings from time to time though. Thatīs why i prefer to connect the animations with an alterable value of the character. Like Alt Val A is 0 _ change to stopped ani, Alt Val A is 1 _ change to walk ani, and so on. And control this value instead ...
Hard to say without seeing the whole code. Maybe there is some overriding by other code snippets.
Thatīs why i said i prefer the value way. Create a counter, and set it always to the Alt Val you use to control the animations. Then you can have a closer look where it refuses to work.