Why my submission are not showing in HN?

Most of your first submissions were slack/discord invites and those will get auto-flagged. Beyond that I can only assume that starting with many discord/slack invites probably flagged the account. The moderator could probably give you more details. Daniel a.k.a. dang: hn@ycombinator.com

New submissions appear on the "new" section. If they get a lot of points and comments they appear on the "top" stories, which is the default when you load HN.

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But they are!