Description of problem:
After updating 16.2.5, customer is facing the same issue in different sites/platforms: live-migrations are failing

The problem seems related to the Scheduler, not able to find an available host (also in an almost empty platform)

Version-Release number of selected component (if applicable):
RHOSP 16.2.5

How reproducible:
Trying to live-migrate a vm

Actual results:
Filter AvailabilityZoneFilter returned 0 hosts

Expected results:
Live migration to succeed

Additional info:
(more info/data will follow in comments)

Customer observed that:
platforms updated from 16.2.4 --> 16.2.5 works fine

Platforms updated from a minor prior to 16.2.4 are hitting the issue
16.2.3 --> 16.2.5 failing
16.2.1 --> 16.2.5 failing