Yup. I feel exactly the same. The first episode was great, watching all the behind the scenes stuff and the birth of some amazing songs and ideas. But by half way through the second episode I'd well and truly tuned out and found myself playing with my phone for most of it.
I suppose it is a lot more interesting for people who know about the producers, sound engineers, etc. But the Beatles were well before my time and something I've only got into in recent years. So I have absolutely no idea who any of these people are, and the series doesn't really go out of its way to explain it.
From my perspective it's just hours of John, Paul, George, and Ringo, p#ssing about in front of a load of hangers on, who all talk over the top of each other with really badly overdubbed audio, so most of the time you have no idea who's talking or what's going on.
I was a massive fan of the way Peter Jackson did They Shall Not Grow Old. It was an absolutely amazing piece of work. But despite absolutely loving the Beatles music, I'm finding this extremely disappointing. The whole thing could have been edited down to a three hour documentary and would have worked much better imo.