I can confirm I have this issue aswell. I am using a wired PS3 controller.
I am on Lubuntu 26.04 LTS. I have tested in evtest and can confirm the controller input works on linux. Additionally controller works on other computers. Since updating to 26.04 I cannot get steam to recognize this controllers input for more than a few moments before it stops and becomes dead until I reboot computer.
Nothing extracted yet.
I'm experiencing issues with controller inputs on Kubuntu 26.04:
I could confirm a few things while steam input doesn't work - to try to rule out an issue at my system's level:
evtestandhid-reportshow all button and axis events).Some system and controller details if that helps:
Steam Beta Branch: Stable Client
Steam Version: 1782866176
Steam Client Build Date: Thu, Jun 25, 2026 12:24 AM UTC -08:00
Steam Web Build Date: Fri, Jun 26, 2026 1:15 AM UTC -08:00
Steam API Version: SteamClient023
That's the extent of my diagnosis, but If there's any extra debug I can run on my end, do let me know.