We have a 2009 Legacy GT with the SI Drive option. You can choose between (S) Sport, (S#) Sport Sharp and (I) Intelligent.
Just today the knob in the center console stopped working and the drive automatically switched to S# mode. Adjusting the knob didn't help and neither did pushing the button on the steering wheel. We shut the car off, let it sit for a minute and turned her back on. It was back in S mode but the knob wouldn't switch to S# or I mode. After driving for about 5 minutes the car automatically switched back to S# mode and we were unable to switch it back without turning the car off.
Any suggestions? Any and all advice would be greatly appreciated, thanks!

Has coffee or soda ever been spilt on the center console?

You know... now that I think of it I think a little soda might have spilled near there. That could very well be what the issue is. How would one fix this, if this was the case? At first I thought it was a neat location for the control, but now realizing how it's directly in front of the cup holders, it could've been better thought out.