one more thing, i just logged into the game and found the exploration achievement gone -.-

I have the exact same problem, i tried to switch 3 or 4 instances and i alawys found the rock unclickable and the "blue beam" already active. I clicked on the 4 datacrons (that were already out) and got the message for receiving codex entries '90', '91', '92' and '93'. But in my codex I can't find said entries (my codex, under the "datacrons" tab states 69/70 entries) I also noticed that i actually had my stat increased be 10.

Player Name: Fafolo Server: Tomb of Freedon Nadd Number of Achievement Points: 22650 screen 1 screen 2