In ncs 2.4.0, this code was executed in power_manager.c when button pressed while powering down:
LOG_INF("Wake up when going into sleep - rebooting");
sys_reboot(SYS_REBOOT_WARM);
In ncs 2.5.0, this does not happen, leading to no more wakeup from that button if pressed again during power down
Note: Still works OK if button not pressed again until after power down is completed
Using custom board with nRF52840