The problem still continues randomly. Yesterday we received two requests. The first request was received correctly. The second request was not received correctly. On the second request the guest information was recorded to the customer database but no payment information was received. The second request appears to be stuck in the cart without any payment method or product requested.
So last night I did a test with my tablet and my Andriod phone. I tried to place a request using each device. When I clicked Proceed To Cart, the checkout only displayed the Guest information but not the Payment Method information. However, I tried a request again with both devices. Instead of clicking on the Proceed To Cart, I held my finger on Proceed To Cart and the popup box showed a choice of Open In Tab. I selected the Open in Tab and the entire checkout form was displayed. I was then about to complete the request.
I have not contacted either person who made requests yesterday. I will attempt to contact them today to get some particulars about their browser, OS, device used, any ad-block apps and any other app that they may be using..