Has you Instagram account been Shadow Banned ?

I'm always getting ton of messages about people's accounts losing engagement and not doing as well as before. If you are shadow banned, you will certainly do a lot worse than before. But how do you get to know if you are shadow banned by Instagram ?
Here is how you find out:

On your main account post a picture and use a hashtag with low share volume. I used #lasvegas2017, only has about ~4000 related posts. I used my 50,000 followers account which would outperform any of the posts in that hashtag because right now the top post for #lasvegas2017 has about ~300 likes.

Once the picture is posted with that hashtag, go on another account that is NOT following the main account (a friend's or whatever) and search for the hashtag #lasvegas2017. In my case, my picture got 800 likes but it did not show up in the hashtag search. If this is the case, you have been shadow banned. This will only work if you are NOT (I repeat NOT) following the main account.

Try again with another hashtag. If it shows the same results, you are definitely shadow banned.

What can I do if I am shadow banned?

Many different possible solutions have been shared before:

1) Deactivating your account for 2 weeks
2) Emailing Instagram support

Note: Neither of these two solutions have been proven to actually work.

Best solution?

Start over with another account, unfortunately.

How do I avoid shadow ban?

Don't buy services from cheap apps and online services, either handle your account manually or work with a professional agency.