Because you should have used a alt account to make it.
Why can't i join my own tournament?
Other members are having this problem.
https://www.chess.com/forum/view/tournaments/no-access-to-daily-tournaments
As described here, you probably can't get access via tournament link and the green "join" button currently since nothing happens: https://www.chess.com/forum/view/tournaments/no-access-to-daily-tournaments
Add "/join" to the original tournament link and you will be registered automatically. I couldn't finde any alternative solution (apart from accepting a tournament invitation via PM by clicking the orange "join" button.
I suppose chess.com is facing a massive bug that affects many if not all members and daily tournaments, I hope this issue will be resolved as soon as possible because it keeps upcoming tournaments completely blocked.
In addition I can't even find my own tournaments in the list of upcoming tournaments (they don't have any restriction like "invites only"): https://www.chess.com/tournaments/all?type=upcoming&sort=start_date
I can't and many others can't.
Help me!!!
Link of tournament:
https://www.chess.com/tournament/50-member-celebration-1