Homebrewing - Beer, Mead, Wine, Cider

Hi!

I noticed that I don't get anywhere close to the gravity Brewfather estimates for a given recipe. Latest example is a SMASH IPA with a good 5 kg of pilsner malt that, which on my BrewZilla Gen 4 should have landed me somewhere around 1.054 pre boil. Everything went according to the recipe: 71 °C strike water, 64 °C mash for one hour (even a tad longer than that due to being interrupted by having kids), nice recirculation all along, no visible dough nests. What I got though was a pre boil gravity of 1.037 (forgot to test for starch being still present with iodine though).

This is only my fourth brew on the system, the first I forgot to measure and two were rather experimental, but I am still noticing a pattern here in that my efficiency is rather consistently sub par. I now wonder where to find room for improvement. For me, there's no need to squeeze every last bit of sugar out of my grains, yet at a mash efficiency of only 54% where in theory I might even get 80% does not only strike me as unnecessary wasteful, this way I don't know if I could even make anything bigger than an IPA at all without stretching the limits of my system.

My grain milling is one of the things that I suspect might contribute. So much so that I already wish I hadn't bought a three roller mill but one that I can adjust with simple advice from the internet, it seems everything in this field is geared towards two roller mills.
Also I started thinking about pH. Until now I never tampered with it, does it really have the potential to make such a huge difference?

All other suggestions are welcome as well. Cheers!