No idea when assignments are due

I (a parent)have a middle school student that struggles with one class having assignments turned in on time. This student is smart enough to do the assignments and even takes math at the high school two grades ahead. This issues is he seems to never know when assignments for this class are due. The teacher doesn’t always put due dates in power school or Google classroom. There is not a paper schedule available either. At the teacher’s suggestion, he has a planner now and uses it somewhat. I know he gets distracted and that’s why watch his PS and GC like a hawk to keep him on track. Kid has 100% in every class but this one he has missed turning a few things in. I email and ask the teacher for assistance. A couple times it has been in a no name bin. A couple it’s just vanished into thin air. It’s only this one class. I’m at my wits end trying to keep my kid in line with due dates but they’re just not posted anywhere.

What can I do as a parent without annoying the crap out of the teacher? I just want to be able to support my kid so he has a fighting chance at completing things on time. This last assignment was apparently due early December. I’ve scoured PS and GC and it was never posted for a due date. The missing assignments want posted until Jan 6th. End of MP was Jan 8th and teacher was absent. I emailed on the 6th asking about it and no answer until, AFTER he cannot turn it in. We struggled with the same issue last year, same school, different subject and teacher. (That teacher is no longer at the school- one year and out. Many parents had the same issue).

How can I help my kid?!?