Syria: they also allowed Russian Islamic extremists to go fight in Syria rather than cause trouble in Russia - some of them reportedly joined ISIS
Dagestan
Sudan/Darfur
disproportionate recruitment of Muslim minorities for the Ukrainian front
violent repression of Muslim minorities
involvement in the Sahel + helping military regimes in Niger/Mali/Burkino Faso fight ISIS affiliated groups
Afghanistan: ISIS have previously attacked the Russian embassy there, saying the Taliban aren’t radicals and are Russian puppets.
Iran: ISIS has perpetrated attacks in Iran, hates the Iranian regime. Iran is a Russian ally and provides them with drones for Ukraine, Russia in turn supports Iran.
Just to add:
Etc. etc. etc.