I hadn't seen this before today, but NY Times claims that around a year ago (after the Jan 6th insurrection), Zuckerberg and Sandberg started to go their separate ways.
"The pair continued their twice-weekly meetings, but Mr. Zuckerberg took over more of the areas once under her purview. He made the final call on issues surrounding Mr. Trump’s spread of hate speech and dangerous misinformation, decisions Ms. Sandberg often lobbied against or told allies she felt uncomfortable with. Mr. Zuckerberg oversaw efforts in Washington to fend off regulations and had forged a friendly relationship with Mr. Trump."
Sandberg has shown herself to be a true champion of moderation. One of her fine achievements at Facebook was to mobilize a team of enterprising Facebook employees to suppress allegations of harassment made against her then boyfriend, Bobby Kotick, from the news.
https://www.nytimes.com/2021/07/08/business/mark-zuckerberg-...
"The pair continued their twice-weekly meetings, but Mr. Zuckerberg took over more of the areas once under her purview. He made the final call on issues surrounding Mr. Trump’s spread of hate speech and dangerous misinformation, decisions Ms. Sandberg often lobbied against or told allies she felt uncomfortable with. Mr. Zuckerberg oversaw efforts in Washington to fend off regulations and had forged a friendly relationship with Mr. Trump."