Basically I was in the hospital and a friend of mine introduced this game to me. He knows I like hoarding loot really often so when I was admitted in the hospital he came by and downloaded put this mod in my steam deck that made the inventory and bags hold so much more stuff it was great, made it slightly hard to read some of the menus but I didn’t care. Since then my steamdeck had to get hard reset and everything was wiped and I’m back to the small inventory space.
Welcome to the forum. 
Might be Smash n Grab. It’s not on the forum any more, but I think you can find it on Nexus.
Thanks!. I looked it up and it not quite it since it looks smaller then what I had lol
Was it Grim UI?
If it was, beware that might not work from tomorrow with the new update as the UI has been completely redesigned, though you will have more stash now anyway.
there are also combo mods that has stuff like that in it, Grimarillion or Dawn of Masteries, but they change the game in additional aspects too not just stash space related (new classes etc). So would depend on if it was a full game mod or just the ui/storage
If you’re playing version 1.3, try this. 