I've been getting a really hard time receiving Channel [Corner], Columns [Corner] & Channel Bridge in the World's Fair rewards, ever since before Update 15. I really ran a lot of exhibitions, in multiple islands, specifically to get these types of ornaments. So far none came up. At all. I even think I was playing another game last time I used to get them.
Thanks for reaching out @blendmode, apologies for the delay!
When completing the World's Fair, there's a pool of rewards you can earn, with there being no guarantee of one over the other.
We have no currently known issues with the drop rate of these rewards, so in this instance, I'm afraid it's a matter of luck as to what you get and if it's something you need as part of your current project or not.
We'll continue to monitor this, but for now this appears to be working as designed.
If there's anything more we can answer, please let us know.
Thank you!
Heya @blendmode , thanks for coming back to tell us the eventual solution to finding these items! That'll be super helpful for other players facing the same issue.
Many thanks to @Asterix201252 for sharing further insights as well 
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