Choose the symptom you are seeing. Start with Android’s child-process setting when Steam will not open or silently closes.
This Android setting can stop Steam from starting or cause it to exit without useful logs. Turn it off before the first launch, or use the in-app “Fix it for me” flow when it is missing.
Start with GPU support, the Linux runtime, and Restrict child processes. Steam also needs to download its client during the first launch.
Restrict child processes should be OFF. A session that closes without an on-screen error can still have logs available through Share logs.
Adreno 6xx is experimental: DirectX 11 via DXVK 2 may run; DirectX 12 games can still crash.
First identify whether the black screen is in Steam or in a game. GPU support, the current release, and scaling settings provide useful starting points.