Problem with Stripe integration

I have just received an email from Stripe that starts " We’ve had some trouble sending requests in live mode to a webhook endpoint associated with your Wiser! subscription account."

Wiser! is the name of my newsletter.

The thing is, I have no idea what this means or how to deal with it. From what I can see, everything is functioning ok. I can’t see where the Stripe integration is in the Settings to check it is OK at my end. And when I look at the Strip dashboard, it looks normal.

Any suggestions on what I should do next?