I’m having this same issue on my Epic Evo. I’ve washed out more on this bike than any other.
To the point where I’m not super confident in this bike.
My Mach4SL would fly thru the same corners, sometimes drifting, but a controlled drift.
Scratching my head to figure it out.
Hump
I’d suggest starting with the geo comparison at BikeInsights to see the sketch overlap and data. Then consider the components not included like stem in particular, but also saddle position. Those won’t go into the chart specifically, but need to be reviewed.
I can possibly help review the data if you’d like. Just need exact year, model and size to start.
The EE has a headtube that is -1* (slacker) than the M4SL. I am comparing a '20 M4SL to a '22 EE7 so because the EE is more slack it is not near as aggressive as a steeper bike on the flat and twisty but will be more confident on situations where the trail is pointing directly downhill - what fork are you using?
The changes I made resulted in a different feeling EE7 to me
Those changes however has made the bike not “as” confident on straight downhills but really made it shred fast flat corners.
It has the Sid Ultimate 110, instead of the 120 that came on it. Factory offset.
And the 20 M4SL with 100mm fork would be the comparison.
Very similar in the stock configuration, the pivot has a steeper HT by 2 degrees.
Epic is longer in the wheelbase, longer rear end.
Sounds just like the comment below about it working well on straight downhill, but not as well on tighter stuff.
The trend of long fronts & short stems just makes weight distribution more tricky. Works relatively well with steeper stuff, and berms on less steep… but not idea for more level ground and flat-ish corners. Demands more effort from the rider to get the chest forward/down to get enough weight on the front tire. Stuff like a longer stem and less saddle setback are ways to tweak on a given bike & size. Flip chips in steep is also a good option when present.
I just updated my post to present the information a little better.
I know it doesn’t sound right, but really slam that saddle forward and see how you feel on it. I dont know how a 110mm fork would perform vs the 120mm or if it would even change/mess with the HTA. I honestly cant imagine the bike without 120mm now that it is dialed in.
I’ve got a 90 stem on it now slammed, but not a negative rise.
The saddle is about 3.5mm behind BB center.
That sounds like a decent forward bias already then.
Exactly,
The only thing now would be to go negative on the stem.
Last fit session, the fitter really liked the body position, but I guess that doesn’t matter if the handling isn’t there.
You probably already looked at this, but considering tire choice may be worthwhile. I tend to setup a tire that is 1 step more “aggressive” than the rear, so I have a basic bias towards grip on the front, with the rear the one more likely to break loose in a basic corner.
Wicked wills front and rear. I’ll play around with the front end, I may be too long and that’s pushing my butt back instead of getting over the front.
I am 50mm behind the centerline of the bottom bracket on a Specialized Power saddle so yes you are most certainly forward as on a regular saddle im probably 10-15mm behind.
I am curious about the stem though, I am still on a 60mm (what came stock) what size frame are you on and what is your height?
I “could” go to a longer stem but I keep seeing/reading that it will mess with the modern geometry. For the record I am 5’9 with a very long inseam and typically can ride a medium or larger (54 or 56 road bike also). In the case of a road bike, my preferred fit on a tarmac is a 56 with 110mm stem and a few mm of spacers under it.
Did you ever try with a smaller stem? Like I said, it felt weird at first to me.
Sort of a related issue, possibly. I had my first official MTB, and the front wheel tended to washout causing rider meeting ground. Embarrassing. The tires were the stock Ground Control’s and I found a Michelin closeout tire that had a lighter tread pattern: smaller and more numerous tread blocks. The LBS sales droid explained that ‘everyone’ hated those tires, and they found they couldn’t give them away (even though I was paying for that one, but anyway) but it looked great (skin wall) and I liked the tread pattern. And on the first ride, the change was night and day! No breakout slides and I stayed on the trail. SUCCESS! So either it was able to compensate for my horrific technique, or lack there of) or the smaller thread blocks and softer rubber did the trick. When I hit a sale on Pirelli bike tires, I got a pair of the one with the similar tread pattern. No complaints from me. 
@teddygram You sound about the same as me. I’m 5-9, longer legs.
As stated above, I’m 3.5mm behind with an ergon smPro saddle. I was running a 90, but put an 80 back on yesterday and raised it a bit. That seemed to feel better.
I don’t have a 70, used to, but I think my wife randomly throws some of my stuff away 
I may try a little further forward on the saddle.
Are you on the Gen7 Epic Evo?
In the last TrainerRoad Pod, Hannah mentioned that she runs her normal race tires with inserts and lower pressure when on slick roots, so your experience on the smaller knobs may be similar
I am on a EE7 also!
See if you can find a 60 or 70 just for testing purposes.
I literally almost have (1) of every size of these in my work bench and a lot of them on my bikes in the garage.
Great for testing and cheap.
I really need to switch to 31.8 bars, it’s so much easier to find stems.
Hump
Chipping in again: What the heck is with manufacturers installing long stems on their bikes? My Roubaix came with a 100! Feels like I was steering from the back 40 after I swapped it for a 60. How many swap stems? Why put such long stems on their bikes, or do I have freakishly short arms for my height? (Or is it made for TT clip-ons to stretch the rider out? But it was marketed as a ‘neo-gravel bike’, ‘Swiss Army knife’ bike, good for everything, so TT on a gravel bike?) But maybe the just want to sell more stems, or SHOULD sell more stems?