POST https://directline.botframework.com/v3/directline/conversations 403 (Forbidden)

Start with the Direct Line REST API base URI documentation referenced in the report, then compare the token-generation endpoint with the conversation POST endpoint and its RegionNotAllowed response. Reproduce the request using the listed URLs and confirm which regional endpoint is accepted; done means documenting a confirmed cause and resolution or identifying that the problem is outside this client library.

I get this error since last week. Our bot worked fine and suddenly started giving us this error. Until last week we used https://directline.botframework.com/v3/directline/tokens/generate to generate a token. We then switched to https://europe.directline.botframework.com/v3/directline/tokens/generate because our resources (Azure Bot, Web App running the bot, WebApp running the web chat; all F0-tier) were created in West Europe last year but with no success.

The exact error is:

{
    "message": "ajax error 403",
    "xhr": {},
    "request": {
        "async": true,
        "crossDomain": false,
        "withCredentials": false,
        "headers": {
            "Accept": "application/json",
            "Content-Type": "application/json",
            "Authorization": "Bearer <Token>",
            "x-ms-bot-agent": "DirectLine/3.0 (directlinejs; WebChat/4.17.0 (Full) 0.15.5)",
            "X-Requested-With": "XMLHttpRequest"
        },
        "method": "POST",
        "responseType": "json",
        "timeout": 20000,
        "url": "https://directline.botframework.com/v3/directline/conversations",
        "body": "{\"user\":{}}"
    },
    "status": 403,
    "responseType": "json",
    "response": {
        "error": {
            "code": "RegionNotAllowed",
            "message": "The request received in france but target regional bot belongs to europe. Please check BaseURI  https://docs.microsoft.com/azure/bot-service/rest-api/bot-framework-rest-direct-line-3-0-api-reference?view=azure-bot-service-4.0#base-uri."
        }
    }
}

The error states that the request is received in france, but none of our resources were created in france. I already renewed the keys of the directline channel, which did not work.

Any help is appreciated.