I had something similar with Lloyds. IE11 wouldn't allow the 'memorable information' page to load properly using Win8.1, although it was OK with Win7. However, all was fine with Firefox using either Win7 or Win8.1.....
Same with booking on-line with Lufthansa for a Germanwings ticket - eventually someone in the 'UK call centre' (probably in Pretoria....) admitted that there was a compatibility problem with IE11, but Firefox should be OK. Which it was......
But isn't Win8.1 truly dire!