When setting "Show Outline" in a structure block to off it disappears but when I reloading the world it reappears this has been an issue since 1.13 but it has never been fixed since and it's so annoying when you have a lot of Structure Blocks in your world, I had to destroy all my Structure Blocks in my worlds because of this issue
Thank you for your report!
We're actually already tracking this issue at MCPE-50739, so I will resolve and link this ticket as a duplicate.
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