The same issue could be with any dynamic interface like PPP that could be don't exists during the boot process/ISP issues

Which version?

Just a heads up that the above script can potentially destroy the config on boot, because if the system is fast enough, the hook will run before the boot config has finished loading. This will result either in an error when commiting because the config is locked (good outcome), or the config not being loaded at all (bad outcome). I've changed it a bit to actually wait for the boot config to load and now it runs safer, but it's still a bit janky in my opinion, I'm still hoping we can get something that works in-system for this case

PR submitted: https://github.com/vyos/vyos-1x/pull/2746

If I connect to the router and issue the commands

PR for 1.4 sagitta https://github.com/vyos/vyos-1x/pull/2732

PR for 1.4 sagitta https://github.com/vyos/vyos-1x/pull/2732

PR:
https://github.com/vyos/vyos-1x/pull/2737

What I noticed is whenever you update rolling versions it breaks dhcp ,but when you make a new install it is fine.
Just to report back

Sorry maybe I’m not understanding you. The address you’ve highlighted isn’t valid in any case (it only has 6 segments). At the very best it should look like 2602:fcad:2:fffe:5054:ff:XXXX:XXXX (with eight segments). 2602:fcad:2:fffe::/64 is a valid prefix on our network, but there would need to be another 4 segments at the end for SLAAC assigned addresses (which is how that particular address is being assigned). I’d need to look deeper into what the correct address should be, which is why we provided the iperf3 example given the shorter / defined host addresses (with the hope that someone else smarter than me might see the pattern of how the addresses are being mangled). Thanks.