I had a world from 1.16.5 u upgraded to 1.17 and then 1.18 pre release 1 and 2 and this happened on new chunks sometimes shipwrecks generate on land for no reason
this makes no sense I think it is a bug
MC-241717
Shipwrecks on land on upgraded worlds to 1.18
Resolved
Duplicate
0
Dupe of your bug, MC-241315
Please do not file duplicate bugs with the same information. It is enough to confirm this is still an issue in the current bug.