I did and I see that there is a short period of time after a PPPoE connection is established when RA's are sent out with a proper valid time. Then it drops to zero until ~2h later, after which it all works until the next reboot/reset. At this time I am done debugging this issue. A 2h wait is not the end of the world, it all recovers automatically, and it already took too much time and effort.
If you have pcaps please open an issue for odhcpd and send the pcap to the devs directly if they request them.