I suspect the delays and other nonsense are more to do with the American election.
The US may, in the background be saying to Ukraine that it needs to accept a negotiated settlement before the US election incase the Orange Random Factor gets in.
With no likely Ukrainian Offensive on the horizon this year or a successful push from the Russians, then we are at a stalemate.
The war could be unlocked with Ukraine being given the ability to Himars (its a new verb I just invented) deep into Russian territory and a large number of F16s.
However that wouldn't bring a ceasefire that Biden needs this summer.