As shown in the screenshot the Rocket 2 on the left wants to go to a launch pad on the right that it not reachable due to barriers, so the second Rocket 1 on the right is blocked and unable to attach.
I tried multiple things like pausing everything and moving the Rocket 2 by hand but it will not give up its reservation on the second launch pad.
It would be nice to have dedicated assembly depots for launch pads.
As for why i'm using 2 different Rocket types i have a space station 3 which only can fit 4 crew members, a rocket 2 can fit 12 members but is more expensive, so i'm using Rocket 1s for Crew members and Rocket 2s for everything else to save on resources.
I know this could be solved by upgrading the station 2 times but i dont want to spend more space station parts than neccessary.





