Your system information

• Steam client version (build number or date):
• Distribution (e.g. Ubuntu): Ubuntu 18.10
• Opted into Steam client beta?: [Yes/No] yes
• Have you checked for system updates?: [Yes/No] yes

Please describe your issue in as much detail as possible:

Games with a joystick set as joystick mouse sometimes revert to joystick move with relativistic mouse.
Ex. Minecraft launched from steam
I am using a ps4 controller if that helps

Steps for reproducing this issue:

1. Add minecraft as a shortcut
2. Set a joystick as joystick mouse
3. Create a world
4. Open your inventory or the escape menu
5. The joystick acts like a relativistic mouse