I recently switched to the one page checkout that Shopify released and it has made an improvement. It helps for customers to see the payment option lower on the page instead of on a completely different page. It’s not a solution but does help.
If you don’t have the one page checkout, go into your Shopify settings>checkout, there should be an option to switch to the new one page checkout.
If not, I have a way to ‘force’ with code..let me know if you need it.