To add another data point.........

I have had exactly identical experience late last week. Cancelled my domestic sector to ABZ on a return from BCN and rebooked me on an earlier connection, giving me 86min connection time. I hope there are no delays or queues!
But no notification and booking disappeared from MMB. I can add it manually but it won't stick.
Cmon BA, you need to tell customers when you are making changes!