Ice hardness can make a big difference.
But, if your blade is aligned right, and you and your clothing and equipment weight at least 100 pounds, it's basically impossible for you to skid. 7/16" or 1/2" ROH are good enough. So something IS wrong.
Are you using a new sharpening pro, or are you taking more steps on the mats off-ice? The tip of the edge may be slightly bent over, or the new sharpener may be handling the sharpening burr a little different. Or maybe he slightly dulls (rounds off) the edges after creating them.
These differences can be too small to see, yet can make a huge difference in your skating. You have to tell by feel, or by how you skate.
Feel the sides of the blade near the bottom. Don't run your finger along the blade - you might cut yourself. Just tap it lightly at many points. If anything is rough or sticks out by feel on the sides, something is very strongly protruding bent over, and is really messing you up. All the sharpness should be on the bottom of the blade, not the sides.
Also - let the edge glide without weight against your fingernail (or if you like your fingernails, a piece of wood). It should very easily slice off a layer, if it is sharp. That has nothing to do with hollow - only how sudden the direction changes are - which is in many ways a more important form of sharpness than hollow.
Many people carry a small flat stone - say 800 - 1000 grit, or even finer, which they use to straighten edges that have bent a bit outwards. I sometimes have also carried a piece of hard leather that I first used to push the edges out a tiny bit, so if the edge was bent inwards, it would be fixed. After straightening the edge, do not take a single step off ice. Sometimes this makes a huge difference in your skating, even when you can't feel anything by the methods I mentioned above.