Builder rules not correctly implemented

[fluffy-chick]

If you add to a feature on which you have previously placed the builder you get another turn. However, at the end of the game, you can lose your extra turn because your opponent already had the last tile in his hand. This is incorrect. The tile should be given to the player with the builder to place

[euklid314]

Yes, this is a well-known bug that is open since 2017. You can upvote the bug report (probably there are several others):

https://boardgamearena.com/bug?id=7601

Unfortunately there seems to exist no active developer who wants to invest time into it.
To be fair, it is probably not trivial to repair the bug since at the moment a new tile is distributed as soon as you finish your move - which is nice since one can plan the next move. That is not compatible with the builder, though.