The new <project>.eqiad1.wikimedia.cloud domain break grid engine because it is highly dependent on DNS naming for host permissions.
This happens on two levels. First, the value of hostname -f is sent to the master as the client ID, and that is compared to the reverse DNS resolution of the IP of the requestor (so this must match the PTR record). That requires fixing the grid servers' /etc/hosts files.
Then the grid will check its config for the hostname (once it is considered matching DNS). Right now, that will not match, and grid_configurator.py has eqiad.wmflabs hardcoded.
So far, I have updated the admin hosts to include the new FQDNs of the master and shadow on tools and toolsbeta.