USER ERROR! Was expanding new maps x4 while pervious were x3

I have a server with my friends, and before the new 1.21 update, our server was on 1.20.4. I had created a map wall with fully zoomed out maps, but it was not completely finished. When I updated our server to 1.21, I went off to create more maps, using my old ones as guides on where to create the next one. I arrive at the next area, go far enough off my old map that the new one won't become the same, and create a new map. It looks like your average map, until it is fully expanded. I arrived in the new area from the North-East corner of the previous map, yet when my new map was fully expanded, I ended up just East of the South-West corner of the new map, when I should have ended up directly at the South-East corner, where I entered from the other one. I tried filling some of the new map out, and then returning to my base to see if it would somehow align, and it definitely did not. 

Steps to possibly reproduce:

1. Create a fully zoomed out map in a previous Minecraft version (I had 1.20.4)
2. Leave, change to 1.21, rejoin
3. Step off that map and create a new map, fully expanding it
4. Place the two side by side

Observations:

1. They do not line up, even though were created side by side

Expected results:

1. The two maps should align seamlessly