Hi Charlotte,
Sorry to hear that you ran into this issue.
We're not seeing this issue reported by other users so it looks like this review request issue is isolated. I did a quick test and can confirm that my review request went through. As a troubleshooting step, please contact your IT team and have them check to make sure that all endpoints listed in this article are added to your organization's allowlist:
If the issue persists, please open a case with our support team here so we can take a closer look at what's preventing the requests from being sent out.