When using the /fillblock command, every tile entity that has a menu/inventory, such as hoppers, dispensers, chests, droppers, etc. cannot be opened/accessed. However, the first tile entity made is accessible. This happens with every version of the /fillblock command (destroy, keep, hollow, outline, replace)
When trying the command with chests, I tried opening the other chests. Their menu doesn't come up, but the first chest displays the opening animation.
Sometimes the menu temporarily opens for a few frames but then immediately closes, and there isn't enough time to interact with the menu at all.