I haven't seen nor can I recommend it, but this movie has grossed $1.5 million at the US box office, and $11.3 million worldwide:

THAT TIME I GOT REINCARNATED AS A SLIME THE MOVIE: SCARLET BOND

From the summary, possibly translated from the original Japanese:

“Corporate worker Mikami is stabbed by a random killer, is reborn to an alternate world. But he is reborn as a slime. His thrown into this new world with the name Rimuru, he begins his quest to create a world that's welcoming to all races.”

(For the record, I have never had a client report having a Past life as a slime.) 

According to Wikipedia, That Time I Got Reincarnated as a Slime is a 20 volumeJapanese fantasy novel series. The books spawned an amine series, with a 3rd season recently announced. The film version was released in November 2022. 

Also, one of the breakout films at the 2023 Sundance Film Festival was Past Lives. It is described as an "aching, deeply romantic debut feature" from writer/director Celine Song but has no connection to Past Lives other than the title. But it got my attention.