Confused About My Reddit Account Suspension — Can Anyone Help Explain?

I registered a Reddit account around 11 PM Tokyo time and posted about RustMailer 1.0 in the r/selfhosted subreddit.
I briefly listed the features and gave some background about the project.

In the next 2–3 hours, the post got over 7,000 views and even received a couple of comments. I replied to one of them.

But when I checked again later that night, my post was gone — and my account had been permanently suspended.

I'm completely confused. What happened?
Did introducing my own project and linking to GitHub somehow violate Reddit's rules?

There was no warning before posting, no message after registering, and no explanation after the ban.

At this moment, I honestly feel a bit defeated. What’s going on?