I’m gonna guess that the anchors on the VerticalLayoutGroup’s RectTransform are not correct and on the build, given different screen dimensions, something degenerate is happening to the overall size, causing it to not be able to flow properly.
Easy enough to prove/disprove: make a custom editor Game resolution that matches what you used in the build and test!
Here are some notes on UI Anchoring, Scaling, CanvasScaler, etc:
Usually you need to choose a suitable ScaleMode and MatchMode in the Canvas Scaler and stick with it 100%. Generally if you change those settings you will often need to redo your UI entirely.
I also use this CanvasScalerOrientationDriver utility to make sharing UI for Landscape / Portrait easier. Read what it does carefully.