GICR_WAKER.ChildrenAsleep conditions to go to 0x0, post PE power-up

As stated in GIC v3 Arch: After powering up a PE, software must set ProcessorSleep to 0 and wait until ChildrenAsleep == 0.

Can you please also state the conditions for GICR_WAKER.ChildrenAsleep to go 0? As in my case at a particular operating frequency of GIC500, for some ARM A53 cores ChildrenAsleep do not go to 0 indefinitely (post clearing ProcessorSleep).

And hence respective cores do not come out of WFI.

P.S. Interrupt targeted to the Core and PE clocks enabled with WakeRequst signal.