The pulse wave scanner has been broken since update 6 in July of 2021, so 15 months now.
It seems to be a Level of Detail (LOD) change, likley made trying to improve performance and FPS that effected it.
The way I work around it is the rocks glow correctly far away (5+km) but then blink off as you get closer and different level of details LOD. Sometimes the rock will stay glowing, but 9 of of 10 times it will just blink off, or colors shift to others around it, whcih that is what people investigate, which is likley people are not noticing and just thinking that there are less crackable rocks, when in reality the rocks no longer highlight when at med and close ranges, and they are not looking for fissures.
I also run where I am flying into the main light source, with night vision on, so I am looking at the shadowed side of the rocks, to highlight the fissures easier. After seeing the rock at distance, then have to fly toward it to identify if it is crackable or not.
For a period of time I was told to send the bug reports direct to one of the CMs on Discord, and I did for updates 6, 7, 8, 9, 10, 11, and 12. Never got any reply back about it being game breaking for core mining overall if you dont know the workaround. New players to the game would not know how to do it at all, so is a broken mechanic.