Fill command doesn't work properly

Hi, I'm creating a procedure with blocks, and the problem is that it kinda works but when I click it, it only fills a single block on the middle of the area, and all the others blocks are invisible and glitch my player when I walk through them. Also, when I put a block in the same position as the pseudo-blocks, the pseudo-blocks turn into the blocks I wanted originally and stop glitching. This works properly when the command is executed by the player, and not on a specified position, but that wouldn't work as I want. When I right click a block on its side, the same bug happens and not even the middle block appears. And to finish, all the blocks that are inside the area don't change, and any non-solid block that was replaced turns solid(but glitchy), and doesn't really update.