Having the same issue on HOD as others. I have also noticed on 2 occasions now when the server is reset and it is way past respawn time nodes will actually move to new locations used as if I already mined them.
Really need Anet to say SOMETHING please because I am tired and frustrated wasting time and money looking for nodes that are not there.
This all started when I like others mined right after the Oct 1st patch and before the second hotfix that night/morning.