"They have been doing things separately for quite a while," one insider tells People. "They were a great couple with a lot of love and respect for each other, but people change and goals change and they weren't the same together anymore."
As for why they split, the purported "industry insider" told the magazine that Momoa, 42, and Bonet, 54, "have grown apart and the pandemic capped it."
Last week, the Aquaman star shared a joint statement on social media that he and Bonet "free each other to be who we are learning to become," adding, "the love between us carries on." (He has since deleted the post.) The couple, who share two teenage children, were together nearly 17 years and married four.
Although Bonet has been famous for almost 40 years, The Cosby Show star is extremely private. Momoa, who launched to stardom more recently, has publicly declared he's the opposite. The actress usually joined her husband on the red carpet, but she was noticeably absent during his Dune press blitz. As Momoa navigates his red hot career, some believe a shift in priorities may have led to the breakup.
"They have grown apart because of different focuses," a source close to Bonet tells People. "A few years ago, Jason was struggling to find work. Now his career is booming. And he wants to keep working as much as he can."
Bonet purportedly has "no interest in joining" Momoa "on every location," adds the source. Distance apparently put strain on their relationship.
"For some people, it might strengthen their marriage. For Lisa and Jason's marriage, being apart has been a disaster," the insider adds.
As the actors said in their statement, they plan to navigate the breakup amicably for their kids, son Nakoa-Wolf, 13, and daughter Lola, 14.
"It's not going to be some scandalous divorce where they trash talk each other," the source notes. "They are both very spiritual and believe in a higher power."
Bonet alluded to change in an interview published one month before the announcement. While speaking with friend Marisa Tomei for Interview magazine, Tomei asked, "What's calling you?"
"Definitely learning how to be authentically me, learning to be new, and following this invitation from the universe to step into this river of uncertainty," Bonet replied. "We've eliminated all this extra noise, and now it's time to grow our roots deeper into our own values."
MORE: Jason Momoa and Lisa Bonet announce separation