The pair announced their split last week after nearly 17 years together and five years of marriage. A source close to Bonet says in this week's issue that the former couple "were amazing for years, until they no longer were."
"They have grown apart because of different focuses," the source says.
The pair's career trajectories have taken them in different directions, according to the source, who explains of the 42-year-old Aquaman and Dune star, "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."
The former Cosby Show actress, 54, "has had no interest in joining" Momoa "on every location," adds the source. "She enjoys her life in L.A.," they say.
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Broadimage/REX/Shutterstock Jason Momoa, Lisa Bonet and family
The source notes that "it's been difficult for them to be apart," and that the distance took a toll on their relationship.
"For some people, it might strengthen their marriage. For Lisa and Jason's marriage, being apart has been a disaster," the source tells PEOPLE.
"It's not going to be some scandalous divorce where they trash talk each other," the source insists. "They are both very spiritual and believe in a higher power."
Mike Coppola/FilmMagic Lisa Bonet and Jason Momoa in 2019
Momoa revealed the news that he and Bonet had split in a now-deleted Instagram post the Game of Thrones alum shared Wednesday. (Bonet does not have social media.)
"We have all felt the squeeze and changes of these transformational times … A revolution is unfolding and our family is of no exception … feeling and growing from the seismic shifts occurring," the joint statement read. "And so we share our Family news that we are parting ways in marriage."
"We share this not because we think it's newsworthy but so that as we go about our lives we may do so with dignity and honesty," they continued. "The love between us carries on, evolving in ways it wishes to be known and lived. We free each other to be who we are learning to become … "
The statement concluded, "Our devotion unwavering to this sacred life our children. Teaching our children what's possible. Living the Prayer. May Love Prevail✨ J & L."