The first news out was that Ukrainian ships had violated Russia’s waters....and IIRC, it was not from Russian media.
“...had violated Russia’s waters..”
Russia seized control of that strait when they took Crimea. Even if you recognize that seizure, Ukraine has freedom of navigation through them.
It’s not “Russian waters”, it is a strait that connects to territorial waters of both countries, that Ukraine and Russia have a formal agreement to share access to. Russia just thinks they can renege on the agreement now that they have annexed Crimea and gotten away with it.