When I posted this to the Sandbox, I have waited for 21 days before I posted the challenge to main. However, there are still a lot of issues in that post, and someone had found a duplicate. Why are there still so many issues in a Sandboxed post when people would have found more issues in the extended time span?
There's really nothing compelling anyone to have a look at the challenges proposed in the sandbox. This is a known issue, unlikely to be solved any time soon.
Your best bet is probably to request feedback in the Nineteenth Byte a few different times during the day and week (to maximise exposure), and especially when a lot of people are active there.
You can also prevent issues by looking at highly voted challenges, and thinking about what makes them good. Trying to solve challenges will also open your eyes for potential issues. You should also have a thorough read through of the Meta posts discussing things to avoid when posting challenges and the tips for writing good code golf questions.
I can't speak for anyone other than myself, but for my part I consider that "challenges" should be challenging, or at least non-trivial. I am therefore not inclined to spend time picking apart trivial questions, which in my view only merit the time necessary to downvote them if they should be posted to main.
In short, more interesting questions are worthy of more attention.