The DSS heatmaps are super unreliable.
No, they are not. And they are not heatmaps. You can
rely on the fact that a specific lifeform will only grow in the blue areas, exclusively. But within these areas, different lifeforms prefer different types of terrain. For example, Bacterium prefer flatland, whereas Fungoida prefer rugged terrain at higher altitudes.
It's a little bit like in our real world: for an edelweiss flower (
Leontopodium nivale), the DSS would show the Alps, the Pyrenees Mountains, the Italian Apennines and maybe some Asian mountain ranges as blue. But within those areas, you'd have to search at altitudes between 1800 and 3500 metres. Not in deeper valleys nor on higher mountain tops.
The entire mechanic of "gotta go 500m away to find another sample

" sucks.
Granted, this can get a bit tedious
sometimes, but if you know what you're doing and have a ship built for this purpose, it's not really a show stopper. Get small nimble ship, maybe one with a see-through floor, fly very low and deploy hardpoints with the composition scanner active (it bleeps if it targets something).
I come across a different sample, and I see more of it in the distance. Giving up on the previous sample, I discard it in order to get the new one. Ten minutes later and two of three of the new sample, want to know what I find? A sample of the previous lifeform.
Yup, that's not the game's fault, that was you not being patient.
