So I tried making another design for an admin panel for my group. I took @mexual computer design and @blve_hxrizon admin panel (big credits to them) and I incorporated them into one, this is what came out of it:
Change the main frame size to fixed instead of dynamic. UDim2.new(scaleX, offsetX, scaleY, offsetY)
What you want to avoid is using scale property outside of frames (parented to main screen). I would recommend doing almost everything inside in offset, except top bars, bottom bars and stuff, it would result in the best scalability of your UI.