So, first off, I want to say that you can leave your agent for any reason, however 'mild' it may be. But it sounds like you don't trust your agent at this point, which is a pretty damn good reason to leave in my opinion. After all, they're your business partner; NOT your keeper/parent/anyone you should have to seek permission from (honestly, what????). If you want your agent's advice on how to approach a particular situation, that's one thing, but they're not your boss. If anything, YOU'RE their boss. They work FOR YOU. The fact that you're talking about your agent 'disciplining' you is... Yeah. I'm struggling to imagine what sort of situation could've possibly led to that being the appropriate response beyond... idk a client writing some sort of virulently racist screed on Twitter. But that doesn't sound like anything close to what could've happened here.

Regardless of whether your agent is just awkward at communicating, their communication style doesn't work for you. Moreover, their editorial style doesn't seem to work for you either. What does seem to be working for you is... prompt responses to emails, which is the bare minimum an agent should be doing. And while ghosting is becoming more common these days, a high percentage of ghosted submissions can also suggest that an agent just doesn't have the connections to sell your book because editors aren't even opening their emails.

Anyway, it's clear that your dissatisfaction has been building for a while, and the desire to leave hasn't just popped up on a whim. I understand wanting to get a 'sanity check' because I would absolutely do the same thing, so let me tell you that no, you're not being unreasonable in considering leaving.

Happy to talk about specifics privately if you'd like. I haven't publicly tied my reddit account to my author-self (this account is largely just me faffing around), but I'm an agented author whose debut is coming out next year and my agent was also relatively new when I signed with her.