No response and/or rejection from potential capstone sponsors

I had what I felt was the perfect idea for a capstone project with my most recent former employer.

I received no response to my initial email, and after a little over a week, reached out via phone. No response.

I thought I left in good standing and was excited about my project so this is a huge bummer. How common is this? What do I do now? My Capstone is in the Fall 2026 semester. I’m worried I won’t be able to find a sponsor that fits my work and research background as well.