LogicApp triggered by MS Forms response with Firewall enabled is not fired

Question

Dear all

We have a Logic App that uses the When_a_new_response_is_submitted in MS Forms connected via microsoftforms connector. We want to have IP filters set to "specific IP Ranges" only and use all IPs of the AzureConnectors Service Tag but this seems to be insufficient and the workflow is not fired as no response is received by the logic app. When we change IP filter to "Any IP" everything works (obviously). Unfortunately we can't see any blocked inbound IP that would indicate what is/are the source IP(s) of the MS Forms Response (webhook).

Does anybody has experience with a similar setup and could tell me what IP ranges we need to whitelist for connecting MS Forms Trigger?

Any support is appreciated.

Thanks and best regards
Stefan