chacha1988

Hello everyone, I was hoping someone would clarify some things for me as despite my trying to find the answer on the internet I couldn't find anything... I'm trying to downgrade my Iphone 6S iOS12 to 11.3.1 and have been trying to find ways to do it online but it seems it's either impossible or this topic hasn't been addressed yet. I found several tutorials online that were all about different versions but the same technique using my version couldn't work either due to obsolete software or perhaps they simply weren't meant to play with this version. I found tutorials for downgrading to 11.4.1 but it's still signed which is why it's easy to find but that version isn't good for me as I'm trying to jailbreak. So my question is, is there any way to downgrade from iOS 12 to 11.3.1? I'd appreciate any opinion and advice... Thank you for your time