Same issue here since this evening (March 10, 2026) on both iPhone and iPad, paid Apple Developer Program account.
After extensive troubleshooting — new certificates, new provisioning profiles, device restarts, testing on both Wi-Fi and cellular — I can confirm this is server-side.
https://ppq.apple.com is returning 502 Bad Gateway intermittently. It sometimes responds with "OK", which makes the issue harder to diagnose as it appears to be working when checked manually.
Awaiting a fix from Apple.
Topic:
Code Signing
SubTopic:
Certificates, Identifiers & Profiles