Newbie problem: how to set enum to variable through switch/ branch/ select?

I have basic coding knowledge and until now I was working in Gamemaker with its scripting language (GML - similar feel to C based languages).

I just started to get into Unreal Engine and went through the stream for Paper2D tutorial. Since it was based on an already pre-set project, I wanted to tweak it further to my liking. I wanted all Flipbooks to be set via state Enums instead of a jumbled mess with different systems together.
I hit a dead-end when wanted to change section that checks if the character is moving (which itself sets Flipbook). I wanted to replace it to set variable holding Enum value for states.
None of these 3 approaches can set the value. Please, can you help out by pointing out what is missing in these configurations?

Thanks for any help!