I will pull the barrel out and make sure that the large and medium slides are indeed closed all the way.
I wouldn't do that.
I find my 55 throws the most consistent charges when the cavity is narrow and deep. I always dial in by moving all three bars out until I'm just under the desired weight. Then I'll adjust the medium and finally the small bar to fine tune. With a small Titegroup load I'd probably leave the large bar in and start with the medium.
The less powder you "cut" on each stroke the more repeatable it will be. But each bar has to step out from the last as previously mentioned.
You can adjust them out with the handle in any position. Do your "in" adjusting with the handle down so you're not trying to mash the powder out of the way...