If standing on Scaffolding and holding shift + space (to place blocks on blocks with interface) weirdly jumping

If I want to place lets say chest next to a barrel but no other block is close but chest and I'm standing on Scaffolding and holding shift + space to place the chest I stard weirdly jumping or bouncing weirdly jumping

PS: I don't know where to post suggestions but when planting potatos or carrots and you don't want to click a lot of times so you hold it but if your hunger bar isn't full you start eating so my suggestion is If players is aiming on farmland don't eat but plant. Nobody would want eat while looking on farmland obviously the player wants to plant.