> I tested here by switching from ifupdown to systemd-networkd and the > system worked perfectly. Do you recommend that I start using > systemd-networkd on the servers instead of ifupdown?
I believe that is the recommendation these days, yes: https://www.debian.org/doc/manuals/debian-reference/ch05.en.html#_the_modern_network_configuration_without_gui. Glad it's working well for you.
