Shopify Forms - Error where some customers cannot close form to place order

[Chris164]

I've had several customers reach out saying that they are not able to close the Sign-up form when trying to place an order.  It does not happen on all devices and I'm yet to find out which ones it's occurring on.  

It's similar to this issue.  Shopify Inbox Keeps Pop out, cannot be closed, customer unable to checkout - Shopify Community

Shopify are wanting to have screenshots of the error, but due to it being only with select customers I'm not able to replicate it.