Hi WanWizard,
I agre with your first part, but not with the conclusion.
The CPU is not overloaded by visible processes.
But the overall system is overloaded.
Load average is not only about CPU. It calculates how long CPU is waiting for network, disks and comunicating with other devices on kernel level.
If the problem is in kernel modul you will not see it in top but in load average yes.
If some kernel modul is doing something nasty, load average will be hight but none process will show it.
Kernel modul could be the problem here.
Thats why somebody should look at it.
Somebody from HiSilicon, becaude this kernel modules contains closed code direct from HiSilicon.