The donor in ticket #210061 reports that after pressing Continue they receive a blank screen. They used Safari 9.0.3 and Firefox 42.0 on a Mac desktop computer running El Capitan 10.11.3. Interestingly, it looks like their details did get transmitted to Ingenico; 2091707027 is an example. We have been able to replicate this as well, with a test donation yielding a blank screen but also transaction 7518606443, which is at status 800 (after which the donor needs to finish the transaction at their bank).
I can dig for the numbers of BPay donations to help set the priority, but it would be great to either fix this if it's easy, or remove the option if it's likely to be protracted.