I don’t think they have any religious basis for this.
The same applies to Russia. You can say something similar about ultra conservative Catholics, since the Pope has called for tolerance. Yet, they would rather denounce the Pope than tolerate LGBTQ+.
The key idea is that bigotry is not driven by religious affiliation, but rather by authoritarian attitudes. That’s what’s common between China, Russia and the ultra conservatives in the US. Tolerance of LGBTQ indicates freedom and liberalism in some sense. And both are challenges to the stakeholders of authoritarianism. They want a world where people live within the framework they dictate - and thus the bigotry.