No Main Landmark when Mat Dialog is Open

When running accessibility assessments I consistently face the "Document must have one main landmark" violation when a mat-dialog is open (despite there being a main landmark in the main shell of our app's markup). When dialogs are closed, there is no issue with this specific violation. I've tried adding a role="main" but this actually causes the accessibility engine to detect both main landmarks and thus reports "Can not have more than one main landmark". Adding role="dialog" to the top level div of the dialog container does not resolve the issue either, though it could be possible that this div level is too nested for a11y to detect the role. Could also be possible this is just an issue inherent in modern modal dialog rendering strategies, as I'm seeing the same violation on other sites such as Facebook and Trello. Curious to hear others' thoughts / assessments on this.

*Note* - I get the same results when testing with both axeDevTools and WAVE


Reproduire le cas du mat-dialog ouvert et exécuter à la fois axeDevTools et WAVE, comme décrit dans l’issue. Déterminer si la violation missing-main-landmark est attendue pour la stratégie de rendu du dialogue ou si elle indique un défaut d’accessibilité du composant ; le travail est terminé lorsqu’une évaluation claire a été établie et, si nécessaire, que le point d’entrée du dialogue concerné a été identifié.

Rédigé par le modèle d'indexation à partir du texte de l'issue.