The placed torches randomly don't emit any light level, when playing with a render distance of 2 chunks, and even the debug screen shows a light level of zero. Often they work fine, but randomly the next one placed doesn't work, even if it's breaked and placed back several times. But once in a while doing that repairs the torch, but not always. Another thing that seems to work more often is place the torch looking in the opposite direction of when it was first placed, but also doesn't always work. With a render distance of 16 chunks it never happens, but I haven't tried any other render distance yet. All this problems where happening while I was digging a tunnel of 2 x 1 blocks and more than 1000 blocks of large, so I'm not sure if it had something to do with it, and I was using the render distance of 2 chunks so the map size didn't get too high, only digging at Y level of 11, above lava lakes. And when that bug happens, even the lava nearby doesn't emit light, nor any redstone ore activated, only sometimes they look like a light source enclosed with slabs, very bright only in the block surrounding the light source.
Please provide a screenshot (F2 key in-game) with the debug screen enabled (hit the F3 key) demonstrating the issue.