Using a touch interface with Prevent Recenter set to true prevents the joysticks from fading to their Inactive Opacity setting.
This also occurred in 4.13.1
When not interacting with the joysticks, their opacity does not fade
Since the Inactive opacity is set to 0.1, it should fade to that opacity when the joysticks are not being used
Head over to the existing Questions & Answers thread and let us know what's up.