Hello Mr. Vadim! I just had a different stability issue with my 32GB Rock. I had to patch new rkbins into my bootimage to get it going stable:
1: https://github.com/rockchip-linux/rkbin/blob/master/bin/rk35/rk3588_bl31_v1.45.elf
2: https://github.com/rockchip-linux/rkbin/blob/master/bin/rk35/rk3588_ddr_lp4_2112MHz_lp5_2400MHz_v1.16.bin
With the help of inindevs great u-boot repo:
(just wget the files into rkbin dir and change makefile accordingly)
I also use Inindevs image idk if it’s compatible or not but maybe you can adapt it smartly to your image
Before I coudn’t allocate any bigger size of ram but now everything butter. (I changed main server with 32 GB and everything went nuts.)
Happy Easter maybe it helps
Edit: and if you try it, I guess it’s best to disconnect power one time on reboot. Maybe Its running slower without your coral and therefore more stable. Who knows