When switching applications or tabbing out of Roblox, if your previous action before doing so was scrolling inside a frame, it will automatically scroll said frame one step in the direction you had already scrolled it. This affects all scrollable elements, including those present in the menu, such as settings. It can be irritating to switch tabs, say to a program that allows you to capture your screen, only for the UI to suddenly move on its own and potentially hide what you were trying to document. Evidently this is not an issue with any hardware or a particular game, as not only does it not occur with other apps, but it affects the in-experience menu as well.
System Information:
CPU: Intel(R) Core™ i5-8300H CPU @ 2.30GHz
Memory: 32.0 GB
GPU 0: Intel(R) UHD Graphics 630
GPU 1: NVIDIA GeForce GTX 1050