The problem is that the meat is swimming in the brine. There is not enough friction because the meat parts don’t touch each other when
there is too much brine. You should put all the meat in the drum, fill 30-40% of the brine, tumble half an hour and put then the rest of the brine in the drum.
The meat is able to absorb the first brine bevor you fill the rest.
Please do the following:
Load all the meat in the tumbler
Load 30-40% of the total brine
Tumble 30 Minutes with cooling -4°C, Vacuum on, Speed: 10 rpm
Check after 30 minutes how much brine is absorbed
Fill the rest of the tumbler in the drum and tumble again