It is my understanding that within the EO they dispute amongst themselves whether or not He actually does proceed from the Son.
There was a series of YT videos put out by this protestant (he had grown up both S. Baptist and non-denominational) who went around and had dinner interviews with all manner of different "christian" religions (Conservative novus ordo guy, novus ordo priest, Orthodox, Episcopalian, pentacostal) to discuss the differences and learn. His goal was to ask questions and learn about the "other side". Very enjoyable talks and good points made on all sides.
But when the protestant had the discussion with the orthodox cleric, this cleric admitted that they didn't really have a problem with the Trinity as explained by Rome. The problem was with authority and how the first ecuмenical councils decided on doctrine vs in the 11th century when the pope "started to take control". It was pretty fascinating to hear the orthodox story.
In a human sense, I get that the Eastern world is more "committee oriented" when it comes to making decisions, while they view the Western world as more "authoritarian". And when you look at the history of Church councils the early doctrines were just agreed to by everyone in attendance, so there was no problem. The committee approach worked (not saying the pope wasn't the head of the Church then, but when you read the docuмents, it says "we affirm" very often and I think the Orthodox view that to mean "committee" vs the pope's use of "we", which means "papal authority for all time".) Anyway, as time went on, heresies got more complex, the world got bigger and the committee approach failed, so the pope had to make a decision. The orthodox answer to error would have endless committees and no results; it's kinda naive in my opinion. But I thought it was an interesting talk.
If you want to see the talk between the protestant and the conservative catholic guy, I also recommend it. The catholic guy converted in high school and then studied theology in college. He's not a Trad but he did a far better job than I could on the topics of church history and some of his theological explanations. There are 5 parts to this interview.