Issue Description:
Facebook and Instagram mobile applications intermittently report “No Internet Connection” on an iPhone, while other apps and web access function normally.

Scope / Impact:

• Affects Meta mobile apps only (Facebook, Instagram)
• Occurs on iPhone
• No impact to Safari or other applications
• User impact: inability to load feeds or content within Meta apps

Environment Details

ISP / Gateway:

• AT&T BGW620-700
• Wi-Fi radios disabled (2.4 / 5 / 6 GHz OFF)

Router / AP:

• TP-Link Deco BE65 Pro
• Mode: Access Point
• Connected via 2.5Gb port on Deco to 10Gb LAN port on BGW620

Network Configuration:

• IPv6: Disabled on gateway (DHCPv6 off; Prefix Delegation on — not user-controllable)
• MTU: 1472
• MAC filtering: Disabled
• Same SSIDs reused from prior AT&T Wi-Fi configuration

Reproduction Steps

1. Connect iPhone to home Wi-Fi (Deco AP)
2. Launch Facebook or Instagram app
3. App reports “No Internet Connection” or fails to load content

Diagnostic Testing Performed

Test A – Browser vs App Isolation

On the same affected iPhone:

• Safari → https://m.facebook.com → SUCCESS
• Safari → https://www.instagram.com → SUCCESS
• Facebook App → FAIL
• Instagram App → FAIL

Result:
Network connectivity to Meta domains is confirmed working via browser.

Findings

• Network path, DNS resolution, and MTU are functioning correctly
• Issue does not reproduce in Safari
• Issue is isolated to Meta iOS applications
• Indicates an application-level transport / iOS privacy / app state issue, not a network or ISP issue

Preliminary Root Cause Assessment

Likely causes include:

• iOS app-level privacy or transport restrictions (Local Network, Cellular, Background Refresh)
• Corrupted Meta app transport cache following network topology change (SSID reuse, AP mode transition)
• Interaction with iOS features such as Private Relay, Limit IP Address Tracking, or cached VPN state

Current Status

• Network infrastructure verified healthy
• Issue isolated to Meta mobile applications on iOS
• No evidence of router, gateway, ISP, DNS, or MTU fault

Requested Support Action

Request investigation into:

• Meta iOS app transport handling under Wi-Fi AP mode environments
• Known issues related to app state corruption after network changes
• Recommended remediation beyond app reinstall and iOS privacy resets