Because I did not instantly go to battle but rather spend 25 seconds doing stuff
There’s a theory out htere that maps change in a predictable pattern with time - so you have to spend a certain amount of time before you get a new map - if you have a short game you can get the same map twice even.
either that or blind chance and confirmation bias! 
This.
Or - sometimes certain maps, like D-Day (This one for sure, Im still not 100% sure after the others) can have 2 variants, that can be differentiated by slighlty changed capture zones placement. Sometimes the game gives you two variants of the same map one after the other.
The algorithm wants you to suffer! 