Legitimate mobile visitors blocked by Code 705 "Failed to verify your browser"

Since real visitors on mobile devices (confirmed on an iPhone, both on WiFi and cellular data) are receiving a "Vercel Security Checkpoint — Failed to verify your browser — Code 705" page instead of the site loading.

What I've already confirmed on my end:

Attack Challenge Mode: disabled
Custom Rules: none configured
IP Blocking: no rules set
Firewall Overview shows "Challenged: 31" in the past hour, with a "DDoS Mitigation" system rule actively firing and traffic spikes in the graph

Thank you for bringing this to our attention. To ensure this is investigated with the necessary priority and privacy, please report all security-related concerns, potential exploits, or abuse directly to the Vercel Security Team.

Please submit your report here: vercel.com/abuse

Reporting via this official channel is the fastest way to reach our security engineers and ensures that sensitive information is handled in a secure environment rather than a public forum.