This has been happening across multiple games for both myself and other players. When you open the chat window, say something, then close it, the game somehow enables the Keyboard and Mouse which essentially breaks games that check to see if the player is on a mobile device or PC.
This has been tested and confirmed with UserInputService, and you can even see the standard Roblox cursor after chatting above the textbox. The odd part is this doesn’t occur with the emulators within Studio and only on the physical mobile device.
Workaround: I have found out you can, for now, create a work around by getting if a device has the MouseEnabled, KeyboardEnabled, and TouchEnabled as soon as they join (aka while loading) then relay it to everything else that requires such information. The only issue with this is by rare chance the mobile device chooses to connect a Mouse or Keyboard during gameplay.