Summary

On iOS 26.4, Proton Mail for iOS exhibits multiple user-facing regressions affecting message formatting, time preference handling, notifications, and performance.

Environment

• Device: iPhone 17 Pro Max
• OS: iOS 26.4
• App: Proton Mail for iOS
• System time format: 12-hour (AM/PM)
• Proton account/web settings: aligned with system settings

Issues Observed

1. Formatting Regression in Reply / Forward Headers

There is a clear regression in how quoted message headers are rendered in both Reply and Forward compose views.

Current behavior (incorrect)
The app inserts a block-style header:

-------- Original Message --------
On Monday, 04/04/24 at 18:18 Jean-Claude <...> wrote:

Previous behavior (correct)
Previously, headers were rendered inline:

On Mon, Apr 4, 2022 at 9:04 AM, Jean-Claude <...> wrote:

Impact

• Affects both Reply and Forward
• Introduces unnecessary visual clutter
• Deviates from prior app behavior (regression)
• Ignores system 12-hour (AM/PM) preference
• Reduces readability compared to the previous inline format

2. 12-hour Time Preference Not Respected

Despite the device being set to 12-hour format, the app inconsistently displays time values, including 24-hour formatting in message contexts.

3. Notification Delivery Issues

Push notifications are:

• delayed,
• inconsistent, or
• occasionally missing entirely,

despite correct system permissions and otherwise normal device behavior.

4. Performance Degradation

• Thread opening and message rendering feel slower than expected
• UI responsiveness does not match current native iOS performance standards

Steps to Reproduce

1. Open Proton Mail on iOS 26.4
2. Open any message thread
3. Tap Reply or Forward
4. Observe quoted header formatting
5. Compare displayed times against system 12-hour setting
6. Send a message to the account and monitor notification delivery
7. Open multiple threads and observe responsiveness

Expected Result

• Quoted headers use clean, inline, locale-aware formatting
• Time display consistently respects system 12-hour (AM/PM) preference
• Notifications are reliable and timely
• App interactions are smooth and responsive

Actual Result

• Quoted headers use block-style formatting with inconsistent time display
• Time format does not consistently match system settings
• Notifications are unreliable
• UI responsiveness is degraded

Additional Context

• Previously reported to Proton Support (Ticket #4079229), closed October 27, 2025 without resolution
• Re-reported April 4, 2026 (Ticket #4629527)

These issues appear to reflect regressions and inconsistencies with expected iOS platform behavior. #96 & #108