Comment 5 for bug 1588877

So the problem is that after third reboot nodes are going into maintenance mode - https://docs.mirantis.com/openstack/fuel/fuel-8.0/operations.html#maintenance-mode

What we need to do in test - disable UMM feature to prevent such behaviour

Quote from docs:
The configuration options are:

    UMM=yes
    REBOOT_COUNT=2
    COUNTER_RESET_TIME=10

where:

UMM
    tells the system to go into the maintenance mode based on the REBOOT_COUNT and COUNTER_RESET_TIME values. If the value is anything other than yes (or if the UMM.conf file is missing), the system will go into the native Ubuntu recovery mode.
REBOOT_COUNT
    determines the number of unclean reboots that trigger the system to go into the maintenance mode.
COUNTER_RESET_TIME
    determines the period of time (in minutes) before the Unclean reboot counter reset.