It seems to be working only when the save mode block's Y level is positive. It doesn't work in negative y levels for whatever reason.
As of 1.18.2, I am still able to replicate this issue.
I was having the same problem
After testing it in 1.17.32, I can confirm that this is still an issue.
It seems to be working only when the save mode block's Y level is positive. It doesn't work in negative y levels for whatever reason.