Comment 14 for bug 1779157

The issue is not seen in either unattended-upgrades/1.1ubuntu1.18.04.9 or unattended-upgrades/1.5ubuntu3.18.10.2 but it should be noted that in the past week the issue was observed only 12 times with 1.1ubuntu1.18.04.8:
https://errors.ubuntu.com/?package=unattended-upgrades&period=week&version=1.1ubuntu1.18.04.8

Considering that only a tiny fraction of the users enable bionic-proposed the issues are unlikely to be observed while the tested packages are in -proposed.

Since the issue is observed rarely anyway I suggest releasing the update to not hold back other fixes and if the issue surfaced again we can look for a different root cause.