The Google Chat transition has begun!
This morning our G Suite domain was switched over to prefer Google Chat over Classic Hangouts. The transition could take up to 24 hours to complete, but during that time Gmail will switch over to use Google Chat as its chat service, you will need to use Google Chat on your mobile devices, and you will no longer be able to use Classic Hangouts from a mobile web browser.
If you have any questions, please check the Google Chat Transition help page or reach out to MLC Network Services. Thank you!