Guild Wars 2

This has happened to my guild twice.
We would complete the rush and then move onto our next mission, but then find out that the rush didn’t complete. We go back to check the rush out and it says we have to do it all over again.
We get 15/15 completed but we don’t get our merits.

It’s known bug. You need to wait on the same map until time runs out. Then you will get the merits for your guild.