Hello, I had a feedback from @ilmich and now I'm back with a couple of device trees you can test on the multitool and see if they change something.
I'm not sure they will fix your issue, because it may be necessary to recompile u-boot too and that would cost me a bit more time to setup the whole thing, but in the meantime you can try these two dtbs overwriting rk322x-box.dtb in extlinux folder of the multitool.
Try both of them and tell me if any (or both) do have any effect
Tudor Dobrota reacted to jock in Can't boot MULTITOOL on OTT MXQ 4K (not Pro) RK3229 box