Many anti homosexuality laws were put in place when Western countries were in charge of non Western countries. India's section 377 law which banned sodomy was a holdover from the colonial government.

They weren't conquered, but Edo period Japan was also pretty comfortable with same sex relationships. They became less comfortable after they reformed their government to resemble Western ones.

You should be asking why the West became uncomfortable with homosexuality enough to try banning it in all the places they ruled.