I don't know of any personally, nor have I read of any. Now, many people with approved NIWs or EB-1As have received RFEs during the I-485 adjudication stage asking for evidence that they continue to work in the same area of expertise as what they won their petitions for. But in all cases I read about, these people (all online cases I've read about) were ultimately approved after providing a simple employment verification letter including their job duties. I don't know what would happen if, in the event of such an RFE, a person is unable to produce such evidence.
Adjustment of Status: EB-2 (NIW) at NSC
Package RD:2/26/07 | FP1: 3/31/07 | FP2: 7/24/08
I-140 AD 6/24/08 no RFE
I-485 AD 9/25/08 no RFE
If you use the word "issue" instead of the word "problem", I am much less likely to respond to you. I am also somewhat less likely to respond if you use the word "back" instead of "ago", or if you use the word "back" immediately after the word "return".