iOS 27.0.1 known bugs: full list (Wi-Fi, Bluetooth, battery, more) — Sept 2026

iOS 27.0.1 has 9 known bugs / issues tracked as of September 22, 2026 — split into 3 bugs fixed in 27.0.1 (Wi-Fi disconnect, Bluetooth pairing, Face ID false rejection) and 6 bugs remaining after 27.0.1 (Mail encryption crash, Apple Intelligence 2 freeze, battery drain, standby drain, Visual Intelligence 2 camera freeze, Apple Pay NFC fails). The remaining bugs are scheduled for iOS 27.0.2, expected Sept 28 – Oct 3, 2026. Workarounds exist for 5 of the 6 remaining bugs (the Mail crash has no workaround — users must stay on iOS 27.0).

This page lists every tracked iOS 27.0.1 bug with severity, affected devices, and whether 27.0.1 fixed it, plus a workaround for bugs that 27.0.1 did not fix.

What are the iOS 27.0.1 known bugs at a glance?

Bug	Severity	Fixed in 27.0.1?	Workaround?	iOS 27.0.2 fix?
Wi-Fi disconnecting intermittently	High	✅ Yes	N/A	N/A
Bluetooth pairing fails	Medium	✅ Yes	N/A	N/A
Face ID false rejection	Medium	✅ Yes	N/A	N/A
Mail encryption crash	High	❌ No	None — stay on 27.0	✅ Expected
Apple Intelligence 2 freeze	High	❌ No	Disable AI features	✅ Expected
Standby battery drain (3-5% overnight)	Medium	❌ No	Disable Background App Refresh for Mail	✅ Expected
Visual Intelligence 2 camera freeze	Low	❌ No	Force-restart phone	✅ Expected
Apple Pay NFC fails (iPhone Air)	Low	❌ No	Restart before tap	✅ Expected
Photos app duplicate thumbnails	Low	✅ Yes	N/A	N/A

What bugs did iOS 27.0.1 fix?

iOS 27.0.1 fixed 3 priority bugs + 4 minor stability issues. The priority fixes shipped because they were affecting flagship iPhone 18 Pro / Pro Max buyers at high rates — Apple considered all three P1 severity.

Priority bugs (fixed in 27.0.1)

1. Wi-Fi disconnecting intermittently — High severity

• Affects: iPhone 18 Pro, 18 Pro Max (most reports), all iPhones on Wi-Fi 6E / 7
• Symptom: Wi-Fi connection drops every 10-30 minutes, requiring manual reconnect or toggle
• Workaround (pre-27.0.1): Forget network + re-add; switch to 5GHz only; disable Wi-Fi Assist
• Fix in 27.0.1: Apple updated the Wi-Fi driver to fix a race condition between background scans and active connections

2. Bluetooth pairing failures — Medium severity

• Affects: AirPods Pro 3, AirPods 4, CarPlay connections, all Bluetooth devices on iPhone 18 series
• Symptom: Pairing request times out; previously-paired devices fail to reconnect
• Workaround (pre-27.0.1): Reset network settings (Settings → General → Transfer or Reset → Reset Network Settings)
• Fix in 27.0.1: Apple updated the Bluetooth stack to fix pairing handshake failures

3. Face ID false rejection — Medium severity

• Affects: iPhone 18 Pro, 18 Pro Max (variable aperture + IR camera alignment)
• Symptom: Face ID rejects the user's face 2-4 times more often than usual, especially in low light
• Workaround (pre-27.0.1): Re-scan Face ID in Settings; use passcode fallback
• Fix in 27.0.1: Apple re-tuned the Face ID model for the new variable-aperture camera on iPhone 18 Pro / Pro Max

Minor stability fixes (also in 27.0.1)

• App Store download progress stuck (all iPhones)
• Photos app duplicate thumbnails (iPhone 18 Pro Max)
• Notification Center gesture race condition (with Siri AI enabled)
• Apple Cash transfer delays

What bugs remain after iOS 27.0.1?

6 bugs are still present in iOS 27.0.1 as of Sept 22, 2026 — all are scheduled for iOS 27.0.2 (expected Sept 28 – Oct 3). The most severe is the Mail encryption crash (no workaround — users should stay on iOS 27.0). The remaining 5 bugs have temporary workarounds.

1. Mail encryption crash — High severity

• Affects: Enterprise users on Exchange / IMAP with TLS encryption, all iPhones on iOS 27.0.1
• Symptom: Mail app crashes when attempting to connect to corporate Exchange servers. Affects ~15% of enterprise users per Reddit r/ios reports
• Workaround: None. Stay on iOS 27.0 (which doesn't have this regression) until iOS 27.0.2 ships
• Fix timeline: iOS 27.0.2 (Sept 28 – Oct 3, 2026) — Apple has confirmed the regression was introduced by 27.0.1's Mail stack update

2. Apple Intelligence 2 freeze — High severity

• Affects: iPhone Air (8GB RAM, with on-device 3B LLM)
• Symptom: Apple Intelligence subsystem (Writing Tools, Image Playground, Genmoji) freezes when processing long inputs. Requires full phone reboot to recover
• Workaround: Disable Apple Intelligence features temporarily (Settings → Apple Intelligence → toggle off)
• Fix timeline: iOS 27.0.2 — likely an out-of-memory fix for the on-device 3B LLM

3. Standby battery drain (3-5% overnight) — Medium severity

• Affects: iPhone 18 series (all models)
• Symptom: 3-5% battery drain overnight when idle. Normal is <1%. Likely a CoreLocation services bug
• Workaround: Settings → General → Background App Refresh → toggle off for Mail (the most common culprit). You can also enable Low Power Mode overnight
• Fix timeline: iOS 27.0.2

4. Visual Intelligence 2 camera freeze — Low severity

• Affects: iPhone 18 Pro (Pro-only feature)
• Symptom: Camera viewfinder freezes for 2-3 seconds when triggering Visual Intelligence via Camera Control button. Affects ~1-2% of captures
• Workaround: Force-restart the phone (hold power + volume up). The freeze doesn't damage data
• Fix timeline: iOS 27.0.2

5. Apple Pay NFC fails (iPhone Air) — Low severity

• Affects: iPhone Air (~1% of units due to Secure Element provisioning mismatch)
• Symptom: Apple Pay tap-to-pay fails to initialize. Phone shows "Apple Pay is unavailable" error
• Workaround: Restart phone before tapping. If that fails, contact Apple Support for a Secure Element reset at the Genius Bar
• Fix timeline: iOS 27.0.2

6. iPhone 18 Pro Max camera app crashes — Low severity

• Affects: iPhone 18 Pro Max (variable aperture models)
• Symptom: Camera app crashes when switching between 0.5x and 1x lenses rapidly. App re-opens to default mode
• Workaround: Pause 2 seconds between lens switches
• Fix timeline: Likely iOS 27.0.2 or iOS 27.1 (mid-October)

What's the most common iOS 27.0.1 bug?

The most reported iOS 27.0.1 bug is the Mail encryption crash — ~15% of enterprise users report it. For non-enterprise users, the most common is the standby battery drain at ~10% of iPhone 18 series owners.

Bug	Estimated affected users
Mail encryption crash	~15% of enterprise users
Standby battery drain	~10% of iPhone 18 series
Apple Intelligence 2 freeze	~8% of iPhone Air owners
Visual Intelligence 2 freeze	~1-2% of iPhone 18 Pro captures
Apple Pay NFC fails	~1% of iPhone Air units

Should I install iOS 27.0.1 with these known bugs?

It depends on which bugs affect you:

User profile	Install iOS 27.0.1?	Why
Wi-Fi disconnect / Bluetooth / Face ID bug	✅ Yes, day one	Your bug is fixed
Mail encryption crash (enterprise)	❌ No, stay on 27.0	Mail regression worse than bug fixes
Apple Intelligence 2 freeze (iPhone Air)	⚠️ Maybe	Only if you don't use AI heavily
Battery drain (iPhone 18)	⚠️ Maybe	Try workaround before installing
No bugs at all	⏸️ Wait	Skip to iOS 27.0.2 directly

For most users (those who were affected by the 3 priority bugs), install iOS 27.0.1 — the fixes are worth the new regressions. For enterprise Mail users, stay on iOS 27.0 until 27.0.2.

When will the remaining bugs be fixed?

iOS 27.0.2 is expected Sept 28 – Oct 3, 2026 with all 6 remaining bug fixes. Apple's internal build activity suggests they're targeting Monday Sept 28 as the public release date, but Friday Oct 3 is the worst case.

After iOS 27.0.2, the next bug-fix window is iOS 27.1 in mid-October 2026, which is a feature drop that also bundles any remaining bugs.

For iOS 27.0.1 release date + general install guidance, see our iOS 27.0.1 FAQ. For what iOS 27.0.2 will fix, see our iOS 27.0.2 FAQ.