While you can make a case that even Stalinism was not nationalistic per se, even official Marxism-Leninism continued to make reference to democracy, and engaged in a charade to pretend that it existed in those states. There was always the danger that the nomenklatura might fall victim to the assertion of democracy from below, and that Marxism-Leninism might succumb to the very democratic tendencies it sought to both exploit and repress.The reality remains that Communism happened in agrarian societies and served chiefly as a means of industrial bureaucratic state-building in societies where there was neither bureaucracy nor state. It never happened as its ideology mandated it should have happened, in any already-industrialized state. Communism was also neither democratic nor nationalistic, and thus is an OTL example that meets all requirements of this OP.
This is why offical communist parties everywhere in the East Bloc, especially after Khrushchev, made it their business to weed out any true-believers from the party apparatus.