Plains temples have numbers 3 and 4 instead of 1 and 2.
How to reproduce
/give yourself a structure block
Set it into LOAD mode
Type in: village/plains/houses/plains_temple_1 or 2
→ ❌ Read the message down below (It doesn't work)Change the title to village/plains/houses/plains_temple 3 or 4
→ ✔ Read the message down below (It works)
So, there are temples 3 and 4. Either the 1 and 2 are unused and don't work, even in structure block or it is a typo.
Similar issue order naming issue with certain savanna village street structures and terminators