I don't see any places for error, unless your reloading room is in an out building where you can't control the humidity. So I have to side with Fred and maybe leave it at "
Poop Happens".
You might look into doing these things to add some insurance...
? If you insist on using TG, then order the optional mini-powder bar Dillon developed for 25Auto. Talk to Dillon and see if this might help.
? Fit a spring or rubber band around the powder bar to make it snap-back on return. A consistent
snap will work to defeat bridging and clumping.
? Lubricate the powder bar with powdered graphite.
Snap-back helper...
There have been several versions of the Dillon Powder Bars. If you'll notice, the photo shows the older black ones, which I believe is an aircraft anti-friction coating for engine parts. I'm not loading near the volume that you are, but still even with this coating I regularly squirt graphite into the hopper.