Get 'Service Provider' and 'Network Domain' dimensions back into your GA4 properties and register them as custom dimensions. Library and service is provided by ipmeta.io.
IpMeta.io for GA4 tag is created by henkisdabro.
Once you set up server side tagging with MetricsGate, you can use this tag with Google Tag Manager to enhance your data analytics.
This tag template is part of an open-source community, with its source code accessible on Github,
and its documentation can also be found online.
You can check its version history below: