When your connection is under 10 mb/s, Roblox’s loading screen when trying to load a game freezes on a single frame and can, rarely, stay on screen after loading has finished. When this rare issue happens, the loading screen does not disappear, but gameplay can be heard under the loading screen and pressing keyboard keys has effects in-game.
This is signaled by the engine loading the selected game’s loading screen, then either freezing on that screen or suddenly transitioning to a gray loading screen. The throbber on the game icon freezes when this issue begins.
System information:
CPU: Intel Core i5-4460 (@3.20 GHz - binned)
Memory: 16 GB DDR3
GPU: NVIDIA GeForce RTX 3060