The banners when they are possible underwater the player (out of water) can see them normally as if they were not in the water.
Note: The player sees the banners normally if the player is in the water. The error is only noticed if the banners are in the water and the player is out of the water
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Thank you for your report!
We're tracking this issue in MCPE-130262, so this ticket is being resolved and linked as a duplicate.
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