Hello,
I've been having the exact same problem. I tried to enrol last weekend was faced with "Contact Us to Continue: Your enrollment in the Apple Developer Program is under review. Please contact us."
I emailed support and they replied three days later with some generic advice about making sure my information was accurate, not using a shared device to enrol, making sure my ID is not expired etc. Then the "Contact Us to Continue" message went away and I was able to resubmit. I made sure everything was accurate and took extra clear photos of my ID against a white background. Again I see "Contact Us to Continue: Your enrollment in the Apple Developer Program is under review. Please contact us."
I have emailed support a second time asking if they can tell me what I should do differently. I will let you know what I hear back. I'm glad I'm not the only one.
My country is Canada (Ontario).