Some folks struggle with IGHs and they just never get them working, for whatever reason. It'll be interesting to see if OP has better results with a derailleur.

I'm running an Alfine 501 with 26/20 on my snowbike and it's on it's fourth season. I have the dreaded Alfine 11 on a commuter and it works very well, again I'm running a lower than expected 39/24 on it.