I have and use the Hornady Lock-n-Load powder dispenser or measurer which ever we call it, circa 2008 ish. I have exact issues as you stated, the longer it is on the worse it gets, even on the slow dispense setting and small case capacity charges are worse. Extremely frustrating and was (sometimes still) going to turn it into a pile of red Hornady dust. My mind set is that it is not working properly and if I broke it and caused it to really crap out I'm out nothing. My working solution is to literally pinch the dispenser tube between my index finger and thumb to slow the rpms, sometimes almost to a stop, it then slows down and goes into trickle mode. This happens usually about 10 rounds in and is why I have my loading short multiple loading sessions as to longer ones to help my frustration levels. I hope this helps you as dumb as this sounds. I've been loading for over 40 years and will not be without a self dispensing powder measurer. I had an rcbs prior to this one(Hornady was my late father-in-law) and I actually think I had fewer overthrows with the Hornady vs rcbs before it started acting goofy anyway. I have gotten use to this nuance and when I don't catch it(slow it down) in time I reset it with the enter button to re-weigh the charge and dump out 6-10 kernels to get what my desired charge weight. 3 kernels of H4350 or Varget is 1 10th of a grain as per Hornady said scale. May not be the answer you wanted to hear but this is a currently working solution to your exact problem. The only time I don't use the Hornady Lock-n-Load is when I'm loading for pistols with ball powders and then I use the old rcbs manual thrower and verify the charge on the Hornady scale. I apologize for the long answer.
I am going to replace it one day but I keep using it this way as described because I would rather put money into more components and keep shooting, as frustrating as it is.
All of this being said what powder dispenser does everyone use recommend? I'm not talking auto v trickles that cost more than our first pickups. This is based on good ole boy equipment operator wages. Y'all prefer red or green, I guess Lyman also?