Rumored to be $5 Regal Monday Mystery Movie May 15, 2023, but unlikely
Reddit has a thread for each $5 (+ tax) Regal Mystery movie:
https://www.reddit.com/r/RegalUnlimited/comments/13599fn/mystery_movie_monday_megathread_may_15_2023/
This one is rated R. The Machine (2023) runtime is longer than most of the Mystery movies. Also Regal posted a hint on twitter that eliminates the Machine and nearly confirms Kandahar as being the Mystery movie.
Kandahar is also rumored, but IMDB does not list a runtime yet. You Hurt My Feelings is also rumored, but was a Sundance festival film.