TPG Community

Get online support

Android apps runs slow and inoperable when using Wi-Fi on SAGEMCOM FAST 5866T

Level 2
Level 2


  • Model: SAGEMCOM FAST 5866T
  • Software Version: SGJy10021E
  • GUI Version: 5.138.5

Android device:

  • Model: Samsung S24 Ultra
  • Android version: 14

Issue Background: Certain apps like Strava, Life360, and Microsoft Authenticator work perfectly on mobile data but significantly slow down when connected to Wi-Fi, especially on home networks. This issue started around four months ago. My only possible theory is TPG has pushed out and updated an 'incompatible' firmware. The router does not match with the ISP infrastructure settings in the backend.


Causes of Slowness: Android devices get IPv6 address as primary DNS server. However TPG (Vodafone ISP) does not support IPv6, this can be verified using the following link:, hence translations and lookups fails, hence the observed slowness when using the Wi-Fi.


Why Mobile Network Works: Mobile networks still primarily use IPv4, allowing apps to function properly. It is an irony but disabling IPv6 is only possible on mobile networks, not Wi-Fi, without rooting the Android device, which risks voiding the warranty.


Non-root Solution: While a non-root solution exists, it poses security risks. Using apps like 'DNS Changer' (AppAzio) from Google Play Store can force Android devices to use IPv4 and Google DNS, resolving the speed issue. I only install to test to verify the issue, use at your own risk when using workaround.


Options for End Users:

  1. Advocate for firmware updates that allows disabling IPv6.
  2. Explore options to roll back firmware updates.
  3. ISP to adopt and support IPv6.
  4. Utilize DNS changer apps to block IPv6.
  5. Consider switching to an ISP.

The purpose of this is to raise awareness and hopefully bring about enough change.