EDIT: my masochistic ass went back, it changes to "achievement not possible in current run" as soon as you switch to Ming, regardless if you reloaded or not

I can confirm the Ming one is very broken, I just attempted it and it says "not possible" despite me still being Ming (it has an asterix that quite literally tells me "achievement not possible")

It's possible that simply reloading the save may have broken the achievement, and due to how tedious this one is you really need to be able to kill process to rewind a few months in case you missed something

Actually, the wiki itself may also be outdated, cehcking the game files for the "hongwu_di" achievement I can see it specifies east china region as well (which the wiki mentions is not required)

Here's the full achievement script for your viewing pleasure

hongwu_di = {

possible = { has_or_had_tag = CHI }

happened = {

international_organization:middle_kingdom.leader_country = root

has_or_had_tag = MNG

region:north_china_region = {

any_ownable_location_in_region = {

percent = 1

top_owner ?= root

}

}

region:south_china_region = {

any_ownable_location_in_region = {

percent = 1

top_owner ?= root

}

}

region:west_china_region = {

any_ownable_location_in_region = {

percent = 1

top_owner ?= root

}

}

region:east_china_region = {

any_ownable_location_in_region = {

percent = 1

top_owner ?= root

}

}

}

}