I think Julen is struggling with the balance of the squad (quelle surprise). He wants to play 4-3-3, but we don't really have the players to make it work. None of the wide players score regularly and are inconsistent - they also play miles away from each other, our forward/s can't hold the ball up, the defence is error prone and the wing backs offer next to nothing going forward. The midfield gets overrun even with three in there.
You've got Kilman underperforming at the back, but the only man suitable to replace him also looks like a bombscare. Kilman probably hasn't been helped by having a mixture of Bueno, RAN & Jonny outside of him. Neves/Nunes/Lemina looked like a perfect balance in midfield for about two games, but now they've resorted to type and Lop hasn't helped by randomly throwing Moutinho/Gomes in there.
Like others have said, Lop needs to start playing players that will bring the best out of what we have here and try to settle on a "best 11". Raul needs someone close to him and Cunha isn't an out & out number 9, so play them together (Cunha just in behind, Neto/Sarabia either side in a 4-2-3-1). Neves & Lemina/Nunes behind.
I've heard Lop say the most important thing is the clean sheet, and I think that's why he likes the three midfielders, one up top - and why he switched to a back three to try and see games out - but if we're not keeping clean sheets, I'd rather he played players that might actually offer a threat going the other way. He's not been helped with all the niggling, annoying injuries we keep picking up, and that must be frustrating for him. But we'd be a lot better if we could play a consistent side, rather than making (unforced) weekly changes and then having to throw a glut of early subs on to try and change the course of the game, IMO.
Sometimes it's easier to keep things simple (I know it's easy for me to say).