One thing someone suggested to me one time is not to ask this question as a closed-ended question. It's really easy for students to mentally go, "Nope, no questions." And that's the end of it.
Instead, try asking it as an open-ended question: "What questions do you have?" This has actually gotten more engagement from my students. They start searching their thoughts for, "Oh, what questions do I have?"
Or you might even set an expectation for talking further: "Let's chat"
But yes, I'm also one to rarely if ever use slides for my classes