So they're both the same, but one works and the other suddenly doesn't?

Yes. Exactly that. This is what is baffling me!

If I were to start troubleshooting this, I would run the Steam client from the terminal and trying to catch any interesting logs when the offending controller goes offline. Steam have a few other log locations, but I can never remember where they live?

If you want to rule out a configuration problem or other issue specific to the Steam installation, you can add a second user, login, start a fresh Steam install and see if you can reproduce the problem.

Also, not sure if you've already know this, but there is an issue tracker for the Linux Steam client:
https://github.com/ValveSoftware/steam-for-linux

It's another avenue to seek help, and with some luck and patience, and if Jupiter happens to be in planetary alignment with Saturn, a Valve employee might show up and throw some light on the problem.

I've moved this to the newly opened Tech Support forum.

Quoting: whizseIf I were to start troubleshooting this, I would run the Steam client from the terminal and trying to catch any interesting logs when the offending controller goes offline. Steam have a few other log locations, but I can never remember where they live?

If you want to rule out a configuration problem or other issue specific to the Steam installation, you can add a second user, login, start a fresh Steam install and see if you can reproduce the problem.

Also, not sure if you've already know this, but there is an issue tracker for the Linux Steam client:
https://github.com/ValveSoftware/steam-for-linux

It's another avenue to seek help, and with some luck and patience, and if Jupiter happens to be in planetary alignment with Saturn, a Valve employee might show up and throw some light on the problem.

I'll have a run through the open/recently closed bugs and see if anything matches, thank you!

Quoting: whizse<snip>
Also, not sure if you've already know this, but there is an issue tracker for the Linux Steam client:
https://github.com/ValveSoftware/steam-for-linux

It has resolved itself with the latest update, so no idea what the problem was... I did note a few recently resolved Switch-type gamepad issues in the bug tracker on github, so thanks for pointing me that way :)

Quoting: JSVRamirezIt has resolved itself with the latest update, so no idea what the problem was... I did note a few recently resolved Switch-type gamepad issues in the bug tracker on github, so thanks for pointing me that way :)

Ah, the problem that solves itself, the best kind of problem!

Fingers crossed that it stays solved!

Fingers crossed too!

I meant to suggest looking at config.vdf and/or saving a copy of it, deleting the original and letting Steam rebuild it. When playing DCS as an added-to-Steam game on Windows, the PS3 controller I was using over Bluetooth sometimes picked up inexplicable stick drift that wasn't present anywhere else.