I have slightly different spoiler arm problem. On sim startup the spoiler arm message is displayed when switch is on or off but spoilers remain retracted. After take off resetting spoiler arm to off does not kill message. On landing the spoilers deploy as normal but will not retract when selected, nothing will retract spoilers until sim is shut down. Until realising what is happening I have been stuck on runway after auto land as auto brake does not release when spoiler arm is cancelled; I can kick the brakes to release.
Everthing worked fine until the latest update. Keyboard / does nothing for me in P3D.