PR4100 won't reacquire IP on reboot or wake from sleep

Since the latest firmware update, the pr4100 won’t reacquire its IP address on a soft reboot or when waking from sleep. This make remote admin (the one I’m worried about is my parent’s NAS) impossible. If the system powers down and boots from a cold start, it is fine. But a soft reboot (the kind that would occur when an app or firmware is updated) results in the machine not attached to the network and an IP address 169.x.x.x.x instead of the LAN 192.x.x.x.x
Simply disconnecting and reattaching the ethernet cable will cause the IP address to be set properly on the NAS BUUUUT that’s a lot to ask of my parents (who are in their 70s and barely understand how their DVR/Plex setup works). And all this was working fine with my ethernet switch/Google Hub prior to the firmware update.
Help.

Have you tried to setup a fixed IP?