Extremely Unprofessional or Just How HHs Work?

I've dealt with some really good headhunters and of course been ghosted by headhunters all the time when recruiting. But this one is just extremely off-putting and I wanted to check if anyone else thinks so, or if it is just how these guys roll sometimes.

Backstory: HH and their firm post a role on LinkedIn. I apply and also reach out directly to HH. I get on a call, seems to have gone well. I send him my resume and they want to chat about a separate role (wasn't too interested, but thought I'd learn about it anyway). They a meeting to discuss.

Time of the meeting comes and HH doesn't call. I call HH -- doesn't pick up. I then send a message asking if they're still free --  no response. At that point, I'm confused, but chalk it up and say it's time to move on. Not the first time a HH has ghosted me for no reason.

A few weeks go by and HH calls me out of the blue. I missed the call and no message left whatsoever. I call back and no response, but I follow up with a message. HH says they want to discuss a role with a firm I would be interested in. We set a time to speak.

Time of the meeting comes and HH doesn't call AGAIN. I call HH -- doesn't pick up.

Has anyone else dealt with this type of situation with HHs or is this extremely unprofessional (which it is)? Should I just not deal with them while searching for a role? 

The role they mentioned was a good one, not one I'd sign for right away, but one that would be a good opportunity. Should I just try to bypass this HH and reach out directly to the firm, burning bridges with HH for future opps?