The guy was a leftwinger during his young years when Portugal was under the yolk of a Fascist Dictatorship, so his relationship with Marxism and Communism was first of the heart and then of the mind.

Of course the Russia as he was taught to believe it was when he was a young revolutionary (the Beacon of Hope for leftwingers who were under the yolk of Fascism, not the Stalinist shithole), occupies a warm place in his hearth and when the bond is emotional it's normal for it to not simply flip On and Off depending on who governs that country.

Mind you, this is a guy who didn't join the Portuguese Communist Party (which was definitelly a tool of the Soviet Union) because he thought it was too top-down authoritarian and instead joined a different, smaller, party that wanted Communism but without the authoritarianism, so he definitelly was and is more than an unthinking tribalist parrot, which is probably why he could be convinced by simply reducing the subject to a question of principle.