I made a post about it to get the word out on reddit: https://www.reddit.com/r/conspiracy/comments/hic4gg/as_of_5_hours_ago_reddit_is_instashadowbanning/

If you make a post that contains any of the following text (not clickable links, just text) your comment will be instantly shadowbanned. If you replace the . with the word "dot" you will still be shadowbanned.

You can only see it is shadowbanned when you log out and view the thread, you will find your comment is gone if you view the main thread.

This is the text:

t h e d o n a l d . w i n

Make a comment in this text in it, and watch your comment disappear when you log out!

What website is so insecure even the mention of alternatives isn't allowed? What is this, North Korea?

And the automated system applied it retroactively as well, so a stickied thread at the top of /r/redditalternatives was removed after being there for months! https://www.reddit.com/r/RedditAlternatives/comments/hi97fz/list_of_active_reddit_alternatives_v5/