Troubles with Priority Group activations after upgrading from 11.4.1HF4 to 11.4.1HF6

Unfortunately I cannot reformat my question above, it won't let me, so here's the configuration in a better readable format, sorry.

ltm pool lbtest_3306 {
    members {
        server1:mysql {
            address 10.19.1.41
            priority-group 100
            session monitor-enabled
            state up
        }
        server2:mysql {
            address 10.19.1.42
            priority-group 1
            session monitor-enabled
            state up
        }
    }
    min-active-members 1
    monitor tcp
}