The thing you likely want to disable is Discord’s in-game overlay , not Roblox’s Shift Lock. In Discord, open User Settings → Game Overlay and turn off Enable In-Game Overlay ; users in Roblox-related posts report that this stops the Shift-related overlay behavior.

What to change

  • Open Discord.
  • Click the gear icon near your username.
  • Go to Game Overlay.
  • Toggle Enable In-Game Overlay off.

If it still happens

  • Check Discord keybinds and remove or change the Shift-related shortcut.
  • Make sure Roblox’s own Shift Lock setting is off if you’re dealing with camera/character locking inside a game.

Roblox side

If you are a Roblox developer trying to disable Shift Lock for players, the Roblox documentation and developer discussions point to turning off the mouse- lock/shift-lock option in StarterPlayer rather than trying to fight it during play.

TL;DR

Disable Discord Game Overlay first, because that is the most common fix for the “Shift + Discord on Roblox” issue.