I think that all non-full blocks don't appear at maps, this is because it's very confusing whenever we need a fence gate shown or the block underneath (grass) because you can see them both at the exact X and Z coordinate.
Well if they labeled something amongst "lava-cauldron" then i wouldn't have created this report
But thanks for letting me know!
If im on the wrong account, then it's me, just 1 year later.
I'm so sorry for not responding after a year,
unfortunately, i cannot reproduce the bug shown in the post
you can close the report.
I and other people cant reproduce the issue you have with the information we've been given
what i think what you meant by "a new installer" is a third-party launcher and if thats what you mean then use the official launcher instead