Numbers of reason could have caused this such as:
- It was caught up in our spam filter.
- A moderator deleted your post.
But what can you do? Here are a few tips :
- Message the channel's moderator and ask them the reason. They're usually friendly people and happy to help you.
- Make sure you are checking the right channel.
- In case you're experiencing the issue in your home feed, make sure to take a look at your feed settings.