Placing down trapdoors of any kind start making nearby textures to change into a solid color at random and generally make it hard to play.
Through further testing, Only the textures on the horizontal axis of blocks are bugged, and texture bugging is not limited to an entire block, just one or two sides can also be affected.
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-44650.
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