Yeah, when I fell back to D4, it was a mixture of a couple of things.
1. I lost a passion for the game for a bit and had the team on sort of autopilot. (I even did this for a few seasons in D3)
2. My arena wasn't ready
3. I still didn't know nearly enough about the game to be able to make a run.
Funny thing is, the only reason I came back to the game was because I drafted a truly stellar trainee. I ended up selling him but drafting a Hof pot player gave me a lot of motivation to play this game again. Once I came back, I tried to soak up as much information as I could in order to be able to train my trainee well. I asked a lot of questions, gathered information from the forums, and learned from some very successful managers in the discord that helped me a lot in getting me where I am now!
I appreciate the question and recommend that you consider joining the discord: https://discord.gg/hnFrchFr
There are a lot of great minds in there that can help you with any questions you may have!