I'm a Master's student at Cambridge, and I emailed a potential supervisor for PhD a while ago. He replied that he was interested to proceed further and asked about my funding details. I informed him that I have already applied for PhD at the university and have already applied for funding. He didnt respond after that, and I had sent him four reminders. His research interests align with mine and would it be rude to show up at his office and request for a review given that he is in the same university?
If you have a scheduling need to get information then, by all means, knock. Apologize for any interruption and ask for a brief meeting, then or soon.
He is probably busy. He is probably willing to accommodate you if you have a need. I would consider it more courteous to knock than to make a phone call, actually.
Need driven interruptions can be forgiven. Don't overthink it.