Comment 2 for bug 1636678

I believe this is probably an issue with ifupdown and how it handles lock files. It appears to randomly allow a dependant interface (bond0.5) to start before its provider (bond0) which means eno1 would never receive the ifenslave.bond0 file and therefore no interfaces are ever attached to the bond.

I've submitted a new bug for that package, with a work around (if you're happy hacking systemd service files)

https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1636708