Interesting. I just reimaged mine this morning for a very similar issue but didn’t run into any problems yet after restore.
Mine crashed while playing Uncharted and after it rebooted it would flip to a black screen when launching a game. Stayed black until the game fully launched and once you quit it would stay at a black screen instead of showing SteamOS. If you hit the volume buttons the screen would stay on until the status bar went away. If you managed to navigate to the desktop it worked fine. Screen came back normal after a reboot but problem would come back after every game launch.
Haven’t gotten to test yet while waiting for games to download. Somehow my sd card got corrupted during the restore so I lost all my downloads.
Working fine all day yesterday playing Black Mesa.
Did you by chance clone your drive when swapping ssd? I noticed a few quirks with mine like verifying install on every boot, screen blinking on and off during sleep process, hitching with the steam button etc. All that seems to have gone away with a full reimage.