There has been a long ongoing issue with PvP defense teams getting corrupted. Here’s one of the bug reports, there are several of them.
Note that the player setting the defense team is seeing it correctly, the player fighting the defense team is seeing something different. It’s somewhat likely that this issue has now propagated to Guild Wars defense teams. What you should be checking is which teams players actually fought, the one set as daily defense or a different one, like the one from the first day repeated. Your battle logs should contain this information.