Temporal Tethers (Sandstorm)

Is this bugged for anyone else only 1 map had one at a boss fight. I did not fully clear every map but I did look around a bit, and I've now cleared all the adjacent maps and only 1 tether?

Whats that about?

[edit: So I cleared this last one I didnt know was connected to it never got the 3 tethers but it opened up]