Problems with popup on iPhone

Hi, we have the Mailmunch plugin installed and configured. When testing on an iphone, the popup displays (on 2nd page the user opens) okay. But when I try to fill out the form, I can get the name field filled in but the form is jumpy and it is impossible to actually finish filling out the form and submit it. Please help! Thanks.

Site is http://www.livingwellinthesouth.com

https://ww.wp.xz.cn/plugins/mailmunch/