The US-Ukraine Ceasefire Plan - Why it's a big problem for Putin

So the US - Ukraine talks in Saudi Arabia conclude with a proposal for a 30-day ceasefire. A full ceasefire, not the partial one the Ukrainians had initially wanted. Why is the distinction between the partial and total ceasefire important - and how did the Ukrainians manage to get a clause inserted that potentially side-steps the trap that Russia and the US had laid for them in their previous summit? Let's discuss.