Can't get the plugin to work within a dev container

[jpomfret]

Hi folks,

I've added the Grammarly plugin to the dev container for my hugo blog repository, but I'm having trouble getting it connected. When I choose >Grammarly: Login / Connect your account from the command pallete I get redirected to a website to Connect Grammarly for VS Code to your Grammarly account when I press continue I get the following popup:

But then when I press open, VSCode comes back into focus but I get the following error:

Request $/handleOAuthCallbackUri failed with message: Minified error #8:  See https://developer.grammarly.com/docs/error-explainer?code=8&args=vscode%3A%2F%2Fznck.grammarly%2Fauth%2Fcallback%3FwindowId%3D1&trace=Error%0A++++at+https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A60282%0A++++at+Generator.next+%28%3Canonymous%3E%29%0A++++at+bt+%28https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A26642%29%0A++++at+o+%28https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A26846%29%0A++++at+https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A26907%0A++++at+new+Promise+%28%3Canonymous%3E%29%0A++++at+https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A26786%0A++++at+Ve+%28https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A60396%29%0A++++at+https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A90543%0A++++at+t.SDK.handleOAuthCallback+%28https%3A%2F%2Fjs.grammarly.com%2Fgrammarly-sdk%401.7%3A17%3A90565%29 for details.

Error Explainer

Any thoughts on why this isn't working?

Thanks