ISIS is supported by Erdogan.
The main question here is not the ones who Erdogan supports. Does 100% of Turkish people support Erdogan? No? Then you can't stereotype a random Turkish guy with ISIS membership without actually knowing him/her.
I know a lot of extremely secular Turkish Nationalists -some of them are even practicing shamanism and refusing being a muslim because believing that original religion of Turkish people is shamanism- who dislike China because of political situations in Xinjiang.
Some Turkish Nationalists even interpret current religious climate in Turkey as an Arab imperialism. And I'm not even talking about secular people who lives not much different then the Western People.