Comment 2 for bug 1753431

There are a number of problems with your configuration in both cases.

For netplan, you shouldn't specify any network-level configuration for an interface that is later expected to participate in a bond. Anything later in the file will clobber anything specified previously, leading to unexpected behavior (or just meaningless configuration entries). Also note that systemd-networkd does not rely on ifenslave for bonding.

For /e/n/i, you're trying to enslave an interface to a bond in two separate places. First by specifying bond-master for an interface, then by specifying a slave under the bond. Remove the physical interfaces from /e/n/i, the bond-slaves parameter for the bonded interface will handle configuring the physical interface. Also, if this is a direct paste of your configuration file, bond-miimon is misspelled. I suspect that might also cause issues.

You're also specifying physical interface configuration in two places: eno3/4 are both being manipulated by both netplan/networkd and /e/n/i.

Lastly, note that you can use a netplan/networkd bond for libvirt/KVM. Personally, I'd migrate your configuration to netplan. That's why I do for my KVM hosts.