Few things to compare with the medium Soul demo bike for you, then you can see how to tweak your setup:
Bar/stem – 70mm x 5deg + 710mm x 50mm rise bars. No spacers under the stem.
Front tyre – Hi Roller 2.35″, rear IKON 2.2″.
I think it’s been covered above, but before fiddling with your forks, try dropping the stem as low as you can, and try a grippier front tyre.
Drop me a line if you want to talk it through more. I would need some more setup details like your current stem length, bar spec, that kind of thing.
120mm is a good sweet spot for people not wanting to constantly adjust their forks, but with 140’s on it the main compromise is your seated position on steep climbs where the front can get a little wandery compared to shorter setting. It certainly still goes round corners great with 140’s on it, so it’s not your fork length per se, it will be something we can solve with your set up.
Cheers,
Cy