Airbnb Sync status blank?

I just went into my Airbnb listings on their site and found that 3 of them had a blank next to the Sync Status section. I checked permissions and Ownerez is still authorised, I then checked OR itself and nothing looks unusual in the API section.

Is this just a glitch, are others aware of this?

We're not aware of any widespread problems along these lines.  It does look like an Airbnb glitch, and you've confirmed everything is in fact working, so that sounds like it's just a display bug.  If it doesn't clear, you could report it to Airbnb tech support to investigate.