Per "Fixed a library compatibility issue that resulted in gamepad support not working" in the 2018-05-18 Steam beta client update, please opt into Steam's beta client and check if the behavior has improved.
This update did fix my XBoxOne S controller not being detected however my Nintendo Switch Pro controller is not recognised (either when connected by USB or bluetooth).
I'd even say there is a new issue, when the Pro connector is attached (but not recognised) Steam and Xbone controllers are detected in Steam and work the UI but are not detected in games (for instance Rocket League) although if I launch Rise of the Tomb Raider it behaves like up and left were being held down. With the Pro disconnected, behaviour is normal in most games but RotTR does not recognise any game pad is connected.
Hello @brain-anti-freeze, please open a separate issue report for the Nintendo controller issue so that it can be tracked properly.
Closing as fixed in the 2018-05-18 Steam stable client update.
I just got a chance to test the May 18th beta, PS3 controller is detected again.
Nothing extracted yet.
Your system information
Please describe your issue in as much detail as possible:
Wired PS3 controller is not recognized in Big Picture mode, but it is functional in games.
Steps for reproducing this issue:
Expected Behavior:
Controller is detected in controller settings, can be used to navigate the UI
Current Behavior:
Controller is not detected or functional in the Big Picture UI. Controller does function inside games.
Additional Information