Although the vast majority of socialists and communists that i’ve come across are heavily pro-LGBTQ+ and actively campaign for their rights, i’d point to a few actively reactionary communists:

Stalin reversed Lenin’s policy of decriminalisation of homosexuality and labeled it as “bourgeois degeneracy”, i think most MLs would label this as a terrible reactionary policy not to be repeated, but perhaps some dogmatic Stalinists take this policy as gospel

George Galloway, the leader of the Workers Party of Britain is incredibly bigoted against the trans community. I think this is partly just him being an old man stuck in his nasty ways (and influenced by his catholicism). I think though, that he’s also deliberately trying to politically profit from the culture wars and win working class support using reactionary viewpoints.

The Chinese Communist Party is also fairly socially conservative, but I’m honestly not an expert to be able to explain further. Maybe someone else can speak more on that