Strange behaviour in building

Tried to add a new section to my borders, but couldn’t start building a wall (can click on start but can’t click on the end - some invisible blocks prevented to do this).

Steps to reproduce:
Just continue build borders

  1. Build floors
  2. Build free standing walls
  3. Can’t build walls - invisible obstacles on my way
  4. Click “Build” after this (may be villagers will show me what they will going to do)

Expected Results:
New wall section to my border

Actual Results:
Villagers are trying to build something “flying” because they have started to build stagings


Version Number and Mods in use: