Heyas Flump and don’t worry about that small stuff. It happens to us all when we’re first doing the dunks.
I hate losing bits of soil too but that’s just our own issue. When u float the pot in a bucket. Just be there for a few mins to let it sink in at some point it may want to seperate from the pot. But usually it doesn’t do that unless I try and actually sink the pot or drown it.
Sometimes I am in a rush wise dunking and I push down and it shoots the root ball out like you said. But just let it float and even support its rim as you swish it around not sinking it down tho. As the medium wicks you the water it will not jump out the pot.
The Reason Doc promotes the dunking is that we won’t be able to under water. Unevenly water. Or over water as long as we let it drop dry well. And saturate the whole pot. Well and dunk on time once the pot is dry of course.
Also the fresh Air and oxygen that gets pulled into the medium when we lift the fully saturated pot is really good.
Please stay the course on these dunks for the time being. Your little baby will be ready for a up can soon and then you will be done with dunking and can top water or half in saucer bottom feed half down the top.
Your doing fine if u really wanna salvage that little soil I have also poured the extra back into the pot.
Try and keep an eye on that Huey tho. 30RH in veg for any extended period is no good.
Cheers Flump have a nice day bud