We have no idea if it has stalled or not, since we don't know what their military objectives (instead of their political objectives) are, and everybody is straight up lying (Ukies now swearing they've killed 11,000 Russians, for example, which is bullshit).
The Russians came in light and not obviously set up to do a traditional war of conquest or even a "decapitation strike" (which I don't think they've ever publicly mentioned). Kiev is - was - a city of 3 million people, so there's no possibility of a decapitation strike without murdering thousands - maybe tens of thousands, or more - of innocent civilians. Which would defeat Russian political objectives, and maybe pull in Nato like Zelensky's been increasingly panicked in demanding.
It looks like the situation on the ground is the Russians are grinding their way towards complete control over the country, its coastline, its critical infrastructure, and the access routes around its major cities, while taking some losses from Ukie resistance. Maybe not as quickly as they expected, but it's a steamroller and not a blitzkrieg. They're also regularly talking to the Ukies, offering terms - none of those terms include surrendering the Ukrainian government or submitting to Russian rule, according to both parties.
If the Russians expected to walk in and install a puppet government, that was dumb. I don't think that was the plan tho - they're aware that Ukies and their Western sponsors won't accept a satellite regime reporting to Moscow, and there's no way of getting that to work while also having an "independent" Donbass. I think they're looking to put Ukraine into an arm lock until they tap out, the US accepts a smaller Ukraine that isn't part or de facto part of Nato and therefore won't be used as a FOB against Russia for military ops and color revolution games, and the Russians withdraw behind the new borders.
Time isn't on Russia's side, but it's not on Zelensky's side either. Neither can afford this to drag out indefinitely. But the Russians can probably, once they've encircled Kiev, camp out and wait to get what they want for longer than Zelensky can maintain a functioning government. That's where the desperation to pull in Nato comes from, with demands for no fly zones (which would instantly mean a Nato-Russia war), escalating war porn on the news, and not very subtle attempts to bait Russian troops into committing atrocities. Desperate people are dangerous, so this could get bumpy over the next week.