Mixed grip has stalled

[ronki23]

I'm currently deadlifting 225lbs without a belt

With a mixed grip where my left hand is overhand and right hand is underhand I can do 4-5 reps

With a mixed grip where my left hand is underhand and right hand is overhand I can barely get 3. And the form is worse on this side

Have had the urge to continue left over and right under but heard it will develop imbalances.

 

[ronki23]

and i'm doing 135-145lbs for 6 reps as a warm up with double overhand grips. Don't remember how heavy I go as it's only the warm up but bar begins to slip out of my hands