What do you mean "Finally"? The protests in Russia started on 24th of February 2022. Over 1000 protesters were detained just in Moscow that day alone. And the protests continued after that.
The problem is, these protests achieved nothing, they only resulted in fines (which undoubtedly went to funding the war), protesters being beaten, detained and some even got a criminal charge. So the protests died down because continuing them only fueled the regime more. Some people shifted to solitary picketing, some started doing online activism, some started sabotaging the railways and burning down enlistment centers, some left the country altogether and some, undoubtedly, just gave up.