I was fighting the wither, when it killed me. It somehow saw me through blocks (MCPE-146594). So I respawn at the world spawn since it broke my bed. I go back, the boss bar appears, so I hide and lower my render distance. After doing that the boss bar disappeared, and can't find the wither. So I flew high up with my elytra, wen't to nearby caves, and explored few chunks in every direction. It's gone. Don't know what happened, but it might be related to my villagers despawning in nether suspiciously at very similar times... MCPE-146599