How to scale HUD correctly when playing in level editor viewport?

I have a portrait view mobile game, and I’m working on the HUD now using UMG. For example for a pointsbar on the top I use some image and a slider. I placed the anchor in the middle, as small as possible, and then i set the correct width of the bar.
Now in most previews (standalone, mobile preview) this works fine. but in the editor preview, it disregards any settings of the camera that makes it 16:9 portrait view, and the HUD bar is sized according to the viewport there (much wider). So that is really annoying (can’t really use the level editor viewport to test out the HUD now) and i can’t seem to find a way to fix it. any ideas?

p.s. screenshot can be provided if needed