One of my sons first voted in NC but moved to Massachusetts and voted there this year. His NC registration was still valid. No they don’t always talk to each other. We got a card from the NC election board and corrected his address which will take care of it. However, it is possible for people to use both ballots.
If you vote in 1 state the other one should be voided for that election. It is the 21st century, so there’s really no excuse.
I just checked. No record of voter registration in old state, with a link for follow up
And guess what, took me to the appropriate website for checking registration in the new state
How bout that?
Easy as pie