Mod being inappropriate, mutes people they don’t agree with? What to do?

Hi, so I won’t say names but in another subreddit there is a mod abusing their power, sending inappropriate DMs and disabling the ability to post in their subreddit when they get triggered by something. It’s very unprofessional and odd. I’m sure I’m not the only one dealing with them. Is there a way to report a specific mod? What do you do in this situation? Thanks

(Using iOS)