Pres. Trump probably thought he was gonna get an unpleasant-but-rational guy like some of the union leaders he had to work with in his New York days ... those guys you can make trade-off agreements with.
Instead, he's finding out that Putin is - like all dictators - a full-blown psychopath, who has no problem with lying, duplicity, mind games, stalling ... same goes for the Hitler, leaders of Hamas, Little Kim, the Iranian mullahs, Ortega (again) in Nicaragua, etc.
They won't deal honestly, they'll play you all they can. Look at how nice Pres. trump was to Kim in Term 1, what did that get in return? More threats, more weapons development.
Pres. Trump and Putin are opposites ... Putin lies, deceives, and kills political opponents, Pres. Trump is honest & up-front, and has never killed a political opponent in his life.