I made a booking for me, my wife, my parents and my wife's parents and the problem is that my wife and my mom have exactly the same names (same title, no middle name, same first and last name). There is no sr/jr mark in our country so there is no way how to distinguish between them during the seat select for example. When I go to MMB on my computer and check the selected seats I can see we have six unique seats assigned for all legs. I also linked all BAEC numbers to all passengers. The problem is when we check the BA app on the phones of my wife and my mom. They both have the exactly same seats on both phones. When I try to change either wife's/mom's seat then after refresh on the phone app they both get the same seat again.
As I said in the MMB and during the seat change everything is correct so the only problem is in the iphone app.

Is it a known bug and it is not a problem?
I read some examples of cancelled ticket from the airline because they thought it is a duplicate booking and this is my biggest worry.