One problem related to transmission solenoid has been reported for the 2017 Subaru Forester. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2017 Subaru Forester based on all problems reported for the 2017 Forester.
When shifting vehicle from reverse to park, then turning vehicle off, the key cannot be fully taken out of the car. The only way to get it out is to restart the vehicle, take it out of park and slam it back into park. Supposedly a switch within the shifter that prevents a solenoid in the steering column from opening. This is all covered on TSB 16-112-18 and there are a lot of people complaining about the issue online.