Disclaimer: I have no idea and it's confusing; I just read a bunch of stories just now; and people lie sometimes. That said, these are the details of the full plan as of a couple weeks ago, which supposedly came from Israel but which they immediately clammed up about whether or not they actually would agree to, not saying either yes or no for quite some time, which was weird. There is still some uncertainty over whether they will "agree to" their own proposal.
Hamas didn't reject the deal but they asked for changes (details not made public and people disagree about what they were and how big they are). Personally I tend to put quite a lot of faith in the Qatari spokesman whose blackly comic summary of the issue was "two fundamental differences; between what Hamas wants as a permanent ceasefire, and what Israel wants as a hostage release and maybe a plan to continue the war."
On that note, someone in Israel's government (no one knows who) said yesterday, "Israel will not end the war before achieving all its war objectives: destroying Hamas’s military and governing capabilities, freeing all the hostages and ensuring Gaza doesn’t pose a threat to Israel in the future." I.e. we get all the hostages back and keep killing you until we feel like we're done, and then at that point, we'll be happy to cease fire.
We finally see the details of what's going on in Israel's government: Sounds like Benny Gantz (who already resigned) and Yair Lapid are supporting the cease-fire, and Bezalel Smotrich and Itamar Ben Gvir have threatened to "collapse the government" if it goes through. Nothing public about what Netanyahu thinks but Benny Gantz cited disagreements with him as why he was resigning.
Both Blinken and Qatar are blaming both Israel and Hamas for doing too much bickering and not enough agreeing to the cease fire. Blinken points out, with maybe a certain amount of validity, that Hamas could have simply said "yes" to the US/Israel/UN/Qatari approved plan already on the table instead of giving the Israelis any room to blame them and keep the war going which is clearly what they wanted to do anyway.