I've had my 550 for over 20 years now & have had a sticky clutch since I got it. Before I start it, key off, I put it in neutral, pull the clutch in & use the kick starter a couple of times. The clutch lets go & the kick starter goes free when the clutch lets go.
Turn the key on, start her up & it goes into gear nice & smooth. Give it a try & let me know if it's okay.