SimPE changed names of Sims when...

I hope this is the right forum to post this question.

Background: Using two HP desktops; old one had Windows 7, new one has Windows 10. Installed the same SimPE version on the new one also. Have all games and EP's thru MG. Got the game running well.

Problem: I copied one of my Neighborhoods from my old computer to my new one. Everything looked good, except the most of the names for my families were changed. I looked in SimPE and except for some of the names of babies, the new names assigned were so random that males now had girl names and vice versa. Otherwise everything else appeared as I left it. In SimPE, I changed the name back to the original one and it's okay now.

Note: Using the exact same custom cc and hacks in the new game as the old one.

Goal: I don't plan on playing this neighborhood anymore and only wanted to move out many of my families to the SimBin so I can then upload the houses, community lots and businesses (after having the Sim close the business) to use those buildings again in another new neighborhood.

But I'm curious why this happened so I can avoid it if I do a future copy & paste. Any ideas?

Thanks.