I have created a new world no cheats enabled just vanilla. I am exploring some caves putting some torches on the way and seems like this bug have not been fixed look at the screenshots. My English is a work in progress feel free to correct me. Thank you.
MCPE-27847
Torches
Resolved
Duplicate
0
Duplicates MCPE-26799.
As a workaround, go to Settings > Video > Smooth Lighting and turn it off.