Boyd Proctor

Hey guys, I have a 2018 Sierra A/T w/ the 6.2, 75000km. I was using a Range AFM disabler but recently stopped. It seems like my truck struggles on cold starts – it takes 4-5 cranks before it will fire up. I replaced the battery as I thought this was this issue but I didn’t help. Cold starts are legit cold starts as in sat outside in -20° C for 12+ hours, it always is plugged in. I’ve also tried to turn the key to on and let the fuel pump prime the fuel system. Once it starts then it’s fine to fire up right away once the key is turned on. Note I was running 87 octane but switched back to 91 octane 2 tanks ago due to the issues. Is this common for the direct injection engines? It seems like a fuel pressure regulator isn’t properly working but these trucks only have a pressure sensor in the tank? Any help is appreciated.