When using the ring of flight (both in singleplayer and multiplayer with flight enabled) creative flight cannot be entered. I have attempted to use the item with my entire inventory empty and nothing changes. When jumping rapidly the fall is slightly slowed in a way that seems like flight is entered and then exited instantly.

Fabric Version: 0.11.6 - 1.17

to add to this, when trying to fly, you get a log spam regarding Player Ability was updated externally

Should be fixed now, thanks for the report!