Laser mining question

Dear Commanders,

I wonder if I understand mining all wrong. Here's how I try to approach it with no result basically.

I built a Dolphin Ship based on D2EA's recommendation for an entry level mining ship.

Then I went over to Miner's Tool to find spots to mine Painite.

I found one in GCRV 1568 and did a scan with my surface scanner.

This showed me some "red circles" and one overlap hotspot in the area I was aiming for.

So I supercruised there tried to drop out exactly in the middle of the overlap.

Now I have been shooting prospector limpet after prospector limpet to find Painite but it is nowhere to be seen.

Is my assumption wrong that it should be easier to spot?

Also, every time I fire the prospector limpet, that computer voice tells me it fails, then I see it starting, impacting the aimend asteroid and providing insights of which minerals that thing has. Why does it say it failed? Isn't that exactly the way it should work?

I also tried to google but couldn't really find a good video that shows how to approach laser mining really. All had either way more sophisticated ships or used lingo, I simply cannot understand.

Thank you for your help.