These are just spearfishing nodes 🙂
They are processed slightly different by the game.
Unlike normal gathering nodes, they are not fully preloaded. Their names are not evaluated until you change to fisher of required level to see them.
The memory allocation module, however, must put them somewhere beforehand – in order to reduce loading time later. Usually it puts them in the same space where previously unloaded objects resided. So whatever names were in that memory will now be attached to invisible spearfishing nodes. In fact, if you teleport to a few more locations and come back, you will trigger memory reallocation and see something else instead.
But as soon as you change to fisher, visible nodes will finish their loading and you will see correct names on 3D Radar.