I made a new world with the old word setting instead of infinite or flat and for some reason i was unable too go up stairs and rugs. I did test a couple things with the stairs too see if they worked but I couldn't find out why and I only directly tested stonebrick stairs and briefly tested black carpet

the video I recorded is bigger than 10 mbs so here's the youtube link 

https://www.youtube.com/watch?v=pFhCi7ca6mM&feature=youtu.be