This hasn’t been an issue since the latest update it’s actually been like that since the release of the new chat/friends.
It’s a minor thing but it’ll be fixed eventually but not very high prio.
Also, it’s not the default that it opens the friends list it just opens what you had open last.
EDIT: Turns out the friends list seems to be the default indeed that’s a bug too.
@davidgardelov, it’s good that he’s reporting these things even if it are small things.
We’ll not be able to fix it all immediately but if nobody reports stuff it might never get fixed because we don’t actively play the game so it’s hard for us to spot these minor things.