Hi @Antonin Audard
Can you provide screenshots of the steps when creating a GPO? For example, is there a Google option in the Configuration setting of Choose which browser opens web links?
According to the documentation, if you enable this policy, you can choose either "System default browser" or a specific browser, such as "Microsoft Edge." "System default browser" refers to the browser setting specified on the user's Windows device.
Users should use Google as the system default browser, and if you have completed all of these steps, please wait for a while, Group Policy may take up to 24 hours to complete the configuration after it is configured.
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