White block entities with fallout texture pack

I have world which uses the Fallout texture pack and while exploring today, I ran into three block-shaped entities. Said entities were just larger than a regular block and wouldn’t break when punched, but seem to be affected by gravity. I should note that the world I use is probably half a year old and was copied from one made in late 2017. Also, this world uses experimental gameplay and the educational items as well.