I also flipped the bike to align the calipers and now I've lost all bite. FFS.
You’ve likely sorted it but you can get most (if not all) of the power back by picking the bike up an inch and dropping it. Pump the brakes after a few drops and it should be good to ride.
You don't have to drop it. Just pump. Recent Shimano stuff is single valved pressure system. We used to have to this to about 50 bikes every Monday after storing bikes in a rental place.
You can leave a hose disconnected for a whole day and still have pressure when you screw it back in.
You’ve likely sorted it but you can get most (if not all) of the power back by picking the bike up an inch and dropping it. Pump the brakes after a few drops and it should be good to ride.