With the launch of the Russian military campaign against Ukraine, protests took place in many Russian universities and regions, but the Russian police apparatus of repression met them with violence and intimidation. Journalists were arrested because they only published reports or mentioned during their statements the Russian war on Ukraine, and those who did not languish in prisons paid sins and signed commitments not to repeat this under the pretext that this incites citizens to hate.
Even if there were Russians who supported the invasion of Ukraine, I think they retracted their opinion after the wave of sanctions that affected their country.
There were protests, but it wasn't massive thing. Few thousands people in whole country protesting probably can't reflect opinion of majority. Yes, you can say that majority remain silent because they're afraid to get arrested, but when you look at things which are going on in Iran, it's only excuses. Probably risk to protest in Iran is bigger than in Russia, but people still do it.
Sanctions? It has smaller influence than majority expected. I hate to say, but I think that Europe is more affected by their own sanctions than Russia. And unfortunately, some sanctions is easily bypased.