I find myself doing those exact kind of 1:1s with my reports and I HATE it. This at least provides, I think, maybe some inspiration on some better questions to ask.
It's perfectly fine to have nothing much to discuss in a monthly 1-to-1. Those meetings are just to set time aside to discuss and to give the opportunity to raise issues or give feedback.
The key, though, is to build trust first. If team members do not feel that they can trust their managers then they won't be open.
I've found that chatting about random, non-work related, things also helps building trust and rapport. Try to make the 1-to-1 an informal chat, not a formal 'interview'.
My one on one conversations with my boss became significantly more productive when we started just going and grabbing a cup of coffee for them.
It's a more social setting, which puts you on footing to actually have a conversation.
The previous six years to that, my boss would ask the same canned questions and I would give the same canned answers. The whole process would take about three minutes and nothing would be gained by anyone.
It's the same with my manager. People don't tell him what they really think, because by experience we know it's not going to have a positive impact, and might negatively impact our raises.
