I'm having the same issue placing blocks at around y=254 to 246 where when I place a block and it flickers the same way as shown in the video my character will take a slight bit of damage and a few seconds later I die and die from "fell from a high place". (I'm placing half slabs at the height if it matters, but it seems like it happens with full blocks too.) So far building above y=256 seems to be fine.
Shlaga
I'm having the same issue placing blocks at around y=254 to 246 where when I place a block and it flickers the same way as shown in the video my character will take a slight bit of damage and a few seconds later I die and die from "fell from a high place". (I'm placing half slabs at the height if it matters, but it seems like it happens with full blocks too.) So far building above y=256 seems to be fine.