Here is my original mailing list post:
https://lists.bufferbloat.net/pipermail/bloat/2024-July/018073.html
Basically if I have sqm scripts enabled, I have issues pulling my address/prefix (I am using WIDE dhcp6c).
If I disable sqm, I get my v6 as expected and renewals continue to work.
This is on a Debian 12 machine, nothing else special.
Let me know what other info you need and I am happy to test/troubleshoot.
Thanks.