It appears the Election Commission is making them. A quick analysis of all the participating voter lists released between 7/16 and 7/23 shows that some people who have already voted are getting their Congressional District information updated.
A very cursory look at the original Participating Voter Lists from 7/16 through 7/21 shows that as many as
37 36 voters had their Congressional Districts changed AFTER they voted.
You can see the results of this first search here.
We’ll keep following these changes as voting continues. I don’t think this is anything nefarious…this is the Election Commission working to correct mistakes.
More later as it develops…