Please watch my FOSDEM talk from 2020, it explains the similar effect in Russia: https://archive.fosdem.org/2020/schedule/event/sdnpof/

The most likely explanation is: the government does not want to block your website, it is collateral damage. They want to block something else, but there is no technical possibility to block that without also blocking your website. This also explains variation between ISPs: there is no centralized solution for blocking. Some of them are using IP-based blocking because they have no technology that would look deeper, some of them block on the DNS level, and some on the TLS SNI level.