Had a similar problem last night tried what I thought was everything but landed back in MMB and picked the individual flight and all of a sudden hey presto I could load my BP to my phone.
Had already managed to get the BP for my connecting flight without any problems. The BP went by email without any problems when I originally checked in.
Had various emails from BA after checking in that there were problems with the required documents that I had already posted.
At the airport no problems just wanted to see vac certification.