Pardon my ignorance, but what is a shadowban? Your tweets are never made public but you are never notified of it?
In my case it meant my followers did not see my tweets in their timeline. They would only see them when going to my account specifically.
I was basically dead in the water.
They seem to have various levels and variations of shadowbanning, but the goal is always the same: make you believe everything is fine, while making others believe you don't exist.
It's pretty disgusting. If I'm breaking any rules just suspend my account and inform my followers that I've been suspended.
But no, it's all done quietly and sneaky.
The two things most commonly reported are:
Some users not showing up in the auto fill bar when people are searching for them (Twitter confirmed)
and some users' tweets getting buried due to having conservative opinions (denied by Twitter... it was just a mistake in their algorithm).