Blank Screen Bug on iOS

Is anyone else experiencing below blank screen bug? It’s making the iOS experience unusable. Force closing the app is a temporary fix but the blank screen returns after a minute or two of use.

Yes, I used Lumo to help generate below bug report. 😆

Bug Report: Lumo iOS/iPadOS — Recurring Black Screen Rendering Failure

Summary: The Lumo app intermittently renders a black screen covering the entire UI except the chat entry box. The issue occurs after a few minutes of normal use and recurs reliably after force-closing and relaunching the app. The app does not crash (process remains alive), but becomes unusable until force-closed.

Reproduction Steps:

• Open Lumo app on iPhone or iPad
• Use normally for approximately 1-2 minutes (timing appears random)
• The main chat/content area goes completely black
• The chat entry box at the bottom remains visible and interactive — text can be typed
• Submitting typed text does not work (no response, no error)
• No gesture or action restores the screen (scrolling, backgrounding/foregrounding, etc.)
• Force-closing the app and relaunching temporarily resolves the issue
• Black screen recurs within a few minutes of resumed use

Expected Behavior: The app should maintain normal rendering throughout a session without requiring force-closes.

Actual Behavior: Black screen renders over the chat content area after a few minutes, leaving only the entry box visible. Submission is non-functional. Only a force-close restores the UI temporarily.

Environment:

• Device 1: iPhone (my device) — running latest iOS public beta
• Device 2: iPad (my device) — running latest iOS public beta
• Device 3: iPad (son's device) — different Proton account, running latest stable iOS release
• Lumo app version: Fully updated (latest App Store version)
• Network: Wi-Fi and cellular both affected

Troubleshooting Already Attempted:

• ✅ Force-close and relaunch — temporarily resolves, issue recurs within minutes
• ❌ App reinstall (full delete + reinstall from App Store) — does not resolve
• ❌ Device reboot — does not resolve
• Occurs across 3 separate devices on both stable and beta iOS — not device-specific
• Occurs on both Wi-Fi and cellular — not network-specific

Additional Notes:

• The app process does not terminate — it appears to be a rendering failure (similar to a Metal/WebKit swapchain or view hierarchy issue) rather than a traditional crash
• The fact that the chat entry box remains visible suggests partial view hierarchy corruption — the lowermost UI element survives but the main content view loses rendering
• The random timing (minutes, not seconds) may indicate a memory pressure or timer-triggered event rather than an immediate initialization failure
• Consistent reproduction across stable and beta iOS suggests the trigger is in the app's code, not an iOS regression
• Contacted Proton separately.