Are you sure you used the Feedback Hub? I never heard of them chatting with anyone, or even replying to any of the Feedback. Supposedly on trending issues they may ask for logs or more information to squash a bug, but I've not seen it yet.
We have complained about this a lot, so maybe they're actually responding now? But chatting, really?
To create a ticket you need to contact Microsoft Support on weekdays by one of these phone numbers:
https://support.microsoft.com/en-us/help/405170...
You can also go here: https://partner.support.services.microsoft.com/... choose the link for Browser help, interact briefly with the robot about your exact problem. If you keep saying it didn't help it will connect you with an agent.
Keep me posted on your progress as I will be here to help until the case is resolved.