It is working as intended - the branch is going to false because your variable is equal to false. If the variables value was true, the branch would use the true wire instead.
Your is Valid node might also be going down the Is Not Valid path, because the Main Widget may not be valid. You need to use Create Widget to create the widget first, and then store it in the Current Widget variable. Then it will be Valid.
I would definitely recommend watching some of the official unreal tutorials on Blueprints, because it seems that you do not fully understand some concepts around Blueprints. You will speed up your learning a lot if you just power through the tutorials instead of trying to make stuff and having to wait for an answer every time you reach a problem. Just a bit of advice 
Good luck and happy developing