Diagonal groups shooting coaching?

[Sunbkpk]

I am getting back into shooting rifles after a couple decades and looking for a little coaching for shooting technique. I am getting diagonal groups frequently with higher recoil hunting rifles. I am shooting off a cement bench with a Caldwell dead shot front bag and rear rabbit ear bag. Ditch the rear bag and I got a horizontal group. Grip the rifle really tight and pulled down into the bags gives the best groups so far but goes against most bench technique. In the distant past was makeshift rests of coats, packs, etc. On whatever support was available with better results. I am pretty sure it is technique as I get it in 2 different higher recoil rifles, the worse the recoil the longer the diagonal group. Checked scopes, mounts, bedded actions and retorqued everything. Tried different loads. Still get either a diagonal group or ok group.
I am thinking poor trigger pull, inconsistent grip, or biasing in bags inconsistently. Other thoughts. Sample group attached is 1 of the worst.

[Sunbkpk]

Horizontal group without rear bag after the diagonal group. Crosshairs moving more Horizontal like this group without rear bag which makes sense. Both bags and I get little crosshair motion.

[hookr88]

I’m assuming 100 yds? And enough time between shots to rule out hot barrel? When you’re holding on target, how does your crosshairs move with your breathing, vertical or diagonal? That’s all I got.

[MADMAX]

Perhaps since you mention higher recoil rifles your flinching
Try a limbsaver pad

[Caseknife]

Is your front sling stud contacting the front bag?  What does the rifle weigh?  Is it a lightweight rifle?  If it is a lighter rifle, 7# or less, have to hold on to them on the bench.  Heavy, low recoil rifles don't have to be held as tight.  How is the sight picture, are you having to pull the crosshairs to the target or is it stable on the bull when you close your eyes and then open them?  How does the butt of the stock fit into your shoulder?  Are you square on the bench or hunched over trying get a good scope view?