it could have water in the exhaust silencer still that is evaporating but it is hard to tell for sure. did you drain it all out?
The rings could be starting to go but usually white smoke is water or moisture instead of oil which is blue.
they arent liquid cooled so theres no antifreeze to burn and create white smoke that way.
i would vote for water in the exhaust chambers somewhere just based on the little bit of info given so far.
take it for a good ride and make sure you get it warmed up well. not a 10 minute ride, more like an hour or more to get everything evaporated off.
steve
2019 Maverick X3 XDS Turbo R
2003 TRX 400EX
2016 HONDA RANCHER