As a casual observer with no particular insight, it appears to me Putin is playing Trump.
Mr. Trump has leverage with Zelensky - he can reduce or stop US aid to Ukraine. However, Mr. Trump has little leverage with Putin, other than escalating the conflict, which would be ineffably stupid. And Mr. Trump is not a stupid man - he would never have intervened in a conflict between belligerents that were formerly part of the same country, in an armpit of the world most Americans can't find on a map, where the US has no vital interests, no clear path to victory, and no obvious exit strategy. Mr. Biden, being both stupid and corrupt, chose to intervene, and Mr. Trump is doing his best to play the cards he's been dealt by Biden and Biden's equally brain-dead supporters...