With Steam Input On, My Controller Does Two Things At Once In Some Games

Your tester result is the key clue: one press, one input. The controller is fine; the game is hearing it twice.

Steam Input works by reading your real controller and presenting a virtual one to the game, and most games only look at that virtual controller. Some games, though, also have their own built-in PlayStation controller support and read the DualSense directly as well. Now the game has two sources, and each press arrives once from each. If the two sources map buttons differently, one press becomes two different actions, exactly as you describe.

The fix is to pick one path per game. Option one: disable Steam Input for that game, so the game reads the DualSense with its native support, which often brings proper PlayStation button prompts and sometimes haptics. Option two: keep Steam Input and turn off the game's own controller or PlayStation support in its settings, if it offers that.

The same doubling happens when DS4Windows runs alongside Steam, or when two remapping tools are active. Any setup where two programs expose the same controller can double up.

Start with option one; it is usually the quickest and keeps the game's native features.