He's been saying the same thing for a decade at least. I don't think he says that he's agreeing with Marxists. He's saying that Marxists want to help poor people and Christians want to help poor people. He's saying that Marxists should be Christians, not that Christians should be Marxists. He wants people to stop being Marxists to be Christians instead. He's using Marxists to achieve his own goals, but I don't think he can be trusted.

His analysis is wrong. Marxism is not simply about "helping the poor". Marxism is an end to economic classes. In the 2018 article that he wrote, he writes that Marxism is wrong because it tries to create heaven on earth.

2013

“The Marxist ideology is wrong. But I have met many Marxists in my life who are good people, so I don’t feel offended.”
https://archive.is/5ejV4

2014

"I can only say that the communists have stolen our flag. The flag of the poor is Christian. Poverty is at the center of the Gospel,"
"Communists say that all this is communism. Sure, twenty centuries later. So when they speak, one can say to them: 'but then you are Christian',"
https://www.reuters.com/article/idUSKBN0F40KZ/

2015

Pope Francis has said he wasn’t offended by the “communist crucifix” given to him by Bolivian president Evo Morales during his South American pilgrimage.
https://www.theguardian.com/world/2015/jul/13/pope-francis-communist-crucifix-gift-bolivia

2016

Asked if his pursuit and support for a more egalitarian society meant he envisioned a “Marxist type of society,” the pontiff said in response, “If anything, it is the communists who think like Christians.”
https://www.telesurenglish.net/news/The-Pope-Hails-Communism-For-Focus-on-Poor-and-Marginalized-20161111-0017.html

2018

The Pope: we depend on God, Marxism is wrong to deny Him
https://www.lastampa.it/vatican-insider/en/2018/05/06/news/the-pope-we-depend-on-god-marxism-is-wrong-to-deny-him-1.34014169/