In the new episode of 9-1-1, fans were surprised by the sudden exit of "Michael Grant," the ex of "Athena" who had been on the show since season 1.

But it now turns out a behind-the-scenes issue led "Michael" actor Rockmond Dunbar to leave the series, and it has to do with the COVID-19 vaccine.

9-1-1 actor Rockmond Dunbar exits after vaccine dispute

Dunbar, 48, has exited 9-1-1 in season 5 because he is unvaccinated and was therefore unable to meet the production's health and safety mandates, according to Deadline.

The actor released a statement that noted he "applied for religious and medical accommodations pursuant to the law" but the studio behind 9-1-1 "denied" his request for an exemption.

Dunbar said he will not discuss the "beliefs and private medical history" which appear to have kept him from getting vaccinated. He added that he "enjoyed the last 5 seasons with this wonderful cast and crew" and will "cherish" his time on 9-1-1.

9-1-1: "Michael" actor Rockmond Dunbar exits after vaccine dispute.

On Twitter, the actor retweeted many messages from fans who were sad about the exit of "Michael" on the Nov. 15 episode of 9-1-1.

He also reposted the news about his departure due to the vaccine conflict. He'd been on 9-1-1 as the ex-husband of Angela Bassett's lead "Athena" since it debuted in 2018.

"Michael" was written out in season 5 episode 8 as his boyfriend "David" is going to Haiti, and he decides to accompany him there.