Scenario

You are seeing messages “This form can’t be distributed as it is asking for personal or sensitive information. Contact your admin for assistance. Terms of use”

or

“Form can no longer be accessed. This form has been flagged for potential phishing. Technical details”

Cause

The reason is Microsoft enabled automated machine reviews to proactively detect the malicious collection of sensitive data in forms and temporary block those forms from collecting responses. Learn more about it.

Solution

Ask your tenant global or security admin to go to the Microsoft Security Administration (Defender) Alerts:

If your list of alers is too big – use filter by Policy: “Form blocked due to potential phishing attempt”.

To unblock the form or confirm it is phishing – admin should open the alert:

And then click “Review this form“.
“Review the form” opens the page “https://forms.office.com/Pages/AdminPhishingReviewPage.aspx?id=<FormId>”
where <FormId> is the form Id.
Here global/security admin can review the form and unblock it or confirm it is phishing:

 

References

• Microsoft: “Review and unblock forms or users detected and blocked for potential phishing“

See also:

• Who is the form owner
• Troubleshooting Microsoft Forms