I run a paper spiggot server and we've recently updated to 1.17 and subsequently  1.17.1. When we updated to 1.17 a new world was created for the players to play on and folk started searching for things such as buried treasure. It became very apparent that the treasure is not in the specified location for the maps, this is the case across multiple different maps for various different locations. I have used world edit to remove surrounding blocks and it is still not there. The same is similar for the woodland mansions. However when hunting for the woodland mansion, I have used the /locate command and that took me to a mansion that does not appear to be there, even when looking for it with the corresponding map. 

I am unsure if this is a server side issue as I've tried investigating it on single player worlds and I've been able to find buried treasures and mansions. I am unsure if this a server issue a general minecraft issue.