I attach a savegame to test the bug, this is how to reproduce it: press the second mouse button over the workshop icon to go there, without moving the screen view, try to build more workshop blocks near it, the green box doesn't appear. If you move the screen, now the green box appears.
My graphics configuration is:
FRONTEND_RES=640x480x32 640x480x32 640x480x32
INGAME_RES=640x480x32 1024x768x32
fx1g0003.zip