Description
During portrait streaming investigation (2026-05-14), dd_resolution_option=auto was not switching VDD resolution despite correct sunshine.conf. Root cause: Moonlight was passing --no-game-optimization which suppresses the optimizeGameSettings=true signal Sunshine requires before applying the auto resolution switch. Fixed in v2.0.41 by removing the flag from pkg/client/moonlight.go.
The removal is not documented. If added back (perf testing, old template copy), portrait streaming silently breaks — VDD stays landscape, no error in any log, only symptom is wrong capture resolution in Sunshine logs.
Action: add a code comment in pkg/client/moonlight.go at the launch args block: do NOT add --no-game-optimization — it suppresses optimizeGameSettings=true which Sunshine requires for dd_resolution_option=auto. Without it, portrait streams silently render at landscape resolution with no error.