Having Difficulty with Widget Size (Add Child To Canvas)

So, I’m attempting to create a pause menu, like would be seen in most non multiplayer games (i.e. press _ key, the game stops and you can access your equip sub menu, map sub menu, etc. When your done press _ key and continue playing). I have gone through multiple tutorials and after piecing together a pause menu tutorial and an inventory tutorial, I’ve basically got what I’m looking for, except, when I add my child widget to my HUD canvas panel, the sizing is not correct, despite adding an auto size, positioning, anchoring, etc.

***The problem is I’m wanting to create a full screen widget for this menu and the size of the widget changes when I go from the editor viewport to fullscreen mode (F11).
It doesn’t fill the screen on the viewport, but does fill the screen in fullscreen mode. I’m aware that means different aspect ratios won’t look right as well. How would I fix this, (keep the widget size consistent ) and is my layout the most effective for what I’m going for? ***
And I am also aware it doesn’t pause or close yet, I thankfully already know how to implement that. (This is my second attempt from scratch).

Here is my blueprint layout. 1st the inventory component function.

My player controller.

My third person character input.
And the issue itself.
Any help would be greatly appreciated! :slight_smile: Thanks in advance.