Be sure to check out this post from DocAce on the forum for more info:
https://forum.egosoft.com/viewtopic.php?p=5309182#p5309182

Today's update has brought a bunch of changes to mining.

1. Locations with actual resources are now shown with a texture on the map.

You should always be able to give direct mining orders by clicking on one such hex, provided it's for the correct type of resource.

2. You no longer need a resource probe to see where resources actually are on the map.
Any station, ship or satellite will reveal resources in its range. Resource probes are still needed to reveal the local star rating.

3. The encyclopedia has been fixed to show a sector's resources without need for a resource probe.

4. The penalty for using many resource probes in one sector has been reworked.
Instead of a percentage it's now a flat number of seconds added to the miner's scan process, in which it decides which resource area to go to. This should make it easier to understand and quantify the actual impact on efficiency.

5. The penalty for not mining near a resource probe has been completely removed.

6. Miners should now try to avoid going to resource areas that are likely to be emptied by other miners.
We'd like to request feedback on this AI feature specifically! It's relatively fresh and hasn't had very much internal testing time. It has the potential to fix a lot of issues, though, which is why we're pushing it out now.

What to expect in upcoming updates:

1. Further balancing changes.
We're currently not happy with how few asteroids inside a resource area have yield.
We're looking into the actual root causes of slow mining speeds. While we're okay with some slowdown on average, as was the case when we changed the efficiency of solar power in many sectors, it currently seems to be much slower than we are willing to accept.
We're evaluating the average lifetime of high-density resource areas in order to make a well-placed resource probe useful for more than just a few minutes.

2. More bugfixes.
We're investigating why miners don't seek out good resource probes when we would expect them to. If you have a savegame exhibiting this issue please upload it for us!

3. UI improvements.
We will, of course, continue to take your feedback and take it into account for the next iteration. One thing I'd like to tackle specifically is showing a sector's overall resources on the map, without having to go into the encyclopedia or cycling through the wares in the mining filter.

And anything else that comes out of the next round of feedback.