The birthday field in the form is preventing us to move to the next page

When we put in a birthday it says the field is required, and it's filled in, but it doesn't recognize it and  won't let you continue. I'll play with it and see what I can come up with. It works fine from my computer but not on a mobile device.

What's your mobile device, the brand and model. I've tested it with Android phone, I was able to submit it without any issues. Did you figure it out? Let us know if you are still experiencing this problem.