Why's that? Have any of the puzzles posted in this over 3,000 post thread ever been chosen for the Daily Puzzle?
Daily Puzzle Submissions! *Be Involved*

@nikk0o: You had a good idea, but you forgot to give the stipulation. The solver deserves to know what the task is. It's also good to show coordinates, and it's customary in compositions to have White move first.

@nikk0o: You had a good idea, but you forgot to give the stipulation. The solver deserves to know what the task is. It's also good to show coordinates, and it's customary in compositions to have White move first.
@n9531l1: Thanks for the feedback. I edited the puzzle to reverse the colors and to include coordinates. I wasn't sure how I should formulate the stipulation though so that it doesn't give away too much information. Do you think just "Find the best move(s) for White" would be sufficient?

If you think giving the normal stipulation would make the problem too easy to solve, you could go with your suggestion.

I thought giving up the queen first (5. Qb8+) and then 6. h4 but that fails because if 5. Qb8+?? Rxb8! (5...Kxb8?? 6. h4!! does indeed draw) 6. h4 then black has 6...Qe8#.

Here is my submission (taken from one of my games, I was playing White and got a win from this position).
Black is ahead in material and set to win, but White has just played Rea1 threatening checkmate on a8. With Black to move, your task is to defend against this threat.
btw how do I post the position so it can be interacted with?

btw how do I post the position so it can be interacted with?
To post a puzzle enter in moves and choose puzzle when choosing theme. If just posting analysis enter in moves but don't choose puzzle.

I have another question re submitting puzzles. When inserting the solution moves, it seems to just allow for one sequence of moves. But what if you wanted to say something like for example move 3. Kh1 OR Kh2 are valid moves.
Otherwise people trying out the puzzle may get frustrated at being marked incorrect for a move that is actually valid (because for that specific move more than one move is valid for the solution).

I have another question re submitting puzzles. When inserting the solution moves, it seems to just allow for one sequence of moves. But what if you wanted to say something like for example move 3. Kh1 OR Kh2 are valid moves.
Otherwise people trying out the puzzle may get frustrated at being marked incorrect for a move that is actually valid (because for that specific move more than one move is valid for the solution).
As far as I know, unfortunately all puzzles here on Chess.com only accept one solution. However you can post a "what if" line that will show up in the analysis once the puzzle is solved, whether with assistance or not.
Thanks