Placed structure is always generated on ground instead of the height the command was executed at

Check underground maybe?

I did and it was there but its not supposed to be underground when I put the command down it does not appear above ground

They only appear below Y=0, so they will be generated there.

The core issue here seems to be that the command claims to have succeeded, when in fact the structure hasn't been placed. (Similar to MC-248183)

Not the same issue, the structure is in fact placed but it is buried, because it is hardcoded to generate at a specific Y level. The same issue happens with bastion remnants.

Thanks for the clarification; I didn't realise that that was the case from reading the description. Maybe this should be made clearer in the report title/description.

Please don't change the Mojang Priority!