Dutch grammar option disabled in Edge Writing Assistance

Thanks for testing this on both managed and unmanaged devices. This looks more like a language-availability gap in Edge Writing Assistance than a policy problem.

The Microsoft Editor language availability page confirms Dutch support in the Microsoft 365 products covered by that article, but it is not a definitive per-language feature matrix for the built-in Edge Writing Assistance experience. The two services do not always expose the same feature set. In particular, Enhanced spell check only confirms that the spelling service is available; it does not mean that the Grammar toggle must also be available for Dutch in Edge.

First, confirm that Dutch is added under edge://settings/languages, is enabled for writing assistance, and that Edge is fully updated. On the managed device, check edge://policy to verify that no policy—such as MicrosoftEditorProofingEnabled—is disabling Microsoft Editor. However, since the same result occurs on a clean unmanaged device, an Intune, Group Policy, SCCM, Windows language-pack, account, or Microsoft 365 licence setting is unlikely to be the cause.

If the Grammar toggle remains disabled on a clean device after those checks, there is no documented Edge setting that can force it on. That strongly suggests Dutch grammar is not currently enabled for Edge Writing Assistance in that build or profile, or that the feature has regressed.

For Dutch grammar checking in the meantime, use Microsoft Editor in Word or Outlook, or the Microsoft Editor browser extension where it is supported.  It is also worth sending Edge feedback with Alt+Shift+I (or Settings and more > Help and feedback > Send feedback), a screenshot, and the Dutch language setting. That gives the Edge team a reproducible language-availability request instead of a generic policy report.