Half-slabs and stairs do not let me walk UP them, They work regularly when stepping down, but when I walk up them I have to jump up each individual step. 

When trying to replicate this issue, I noticed it is only within 16 blocks of the border for the OLD WORLD map's edge. The stairs and half slabs work as normal everywhere else in the OLD type worlds. This is very unfortunate, as my castle is right on the edge of the map. 

I do not know if this happens in survival, I am in creative. Also Ladders and Scaffolding work normally. Only Stairs and Half Slabs have an issue.