As I stated - these are generated according to various BGS factors and them moving is "more of a stretch but not out of the question.". I have chased this up with the devs and I'm afraid they will not be reverted to how they were Pre 3.0 - this is due to various reasons. This also echo's our Support teams response:
Thanks for your message regarding this problem. I'm sorry this has happened.
The placement of low and high resource extraction sites is controlled by an algorithm. This bit of code has been changed slightly in the last update and as a result, some sites may have moved.
Unfortunately, it will not be possible to restore individual resource sites to their former position. However, there should still be sites around that are similar to the place you used before.
I am sorry that I cannot be of greater assistance in this matter
Apologies for any frustration caused by this!
Fly safe Cmdrs! o7