Mobile data completely broken after most recent update

[kyeb]

My Zenfone 10 has been totally unable to connect to any internet over mobile network since the most recent update (35.0604.0404.109).  I'm using T-Mobile in the US.

This sucks, I really liked this phone, and only bought it a year ago. But it's totally unusable without mobile data.

The symptoms are super weird - the status bar shows signal, but there is no connection. It initially shows "4G" or "5G" with the connection not working, then after a minute, the status bar changes to showing an "E." SMS, calls, and WiFi all work fine - it's only internet over the mobile networks. I contacted support, and all they did was walk me through the steps in https://www.asus.com/us/support/faq/1011478/, which I already had tried (except for factory reset).

Is there a fix being worked on for this, or is it time to just give up on Asus and go over to iPhone? This is an insane bug to release.

[kyeb]

Yeah, I almost certainly won't buy another Asus phone after this, it's already caused far too much pain.  Any tips on APN settings? Not sure where to start there.

[Riquende]

Hi Kyeb, this might not be related to the update. I bought my Zenfone last July and after about a month I had the exact same symptoms you're describing, on EE's network in the UK. It did have a connection, showed E, and I'd get notifications I think. Occasionally even load a basic website after waiting a few minutes, but for anything like Google Maps, or Audible etc, forget about it.

In the end I had to RMA the phone and Asus repaired it, and it's been fine since. 

[kyeb]

Interesting @Riquende , sounds similar! Did you try factory resetting? I haven't done that yet, since it's a ton of work, but would rather try that before RMA-ing it.

[Malisha]

Let’s break this down and see if there’s anything else that might help, even if a complete fix is still in the works from ASUS.

1. Check APN Settings (Again)

You mentioned that you’ve already tried a lot of the troubleshooting, but let's give the APN settings another careful look. Sometimes updates can reset APN settings, which could explain the lack of mobile data despite the network signal being present.

• How to manually set APN settings for T-Mobile on your Zenfone 10:

  1. Go to Settings > Network & Internet > Mobile Network > Access Point Names.

  2. Add a new APN or edit the existing one with the following T-Mobile settings:

     • Name: T-Mobile US

     • APN: fast.t-mobile.com

     • MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc

     • MMS Proxy: 216.155.165.50

     • MMS Port: 80

     • MCC: 310

     • MNC: 260

     • Authentication Type: None

  3. Save the settings and restart your phone.

  4. If this doesn’t resolve the issue, consider trying Reset Network Settings (Settings > System > Reset > Reset Wi-Fi, mobile & Bluetooth) — this will reset APNs and network-related settings.

2. Switch Network Mode (Try Different 4G/5G Settings)

The status bar showing “4G” or “5G” and then dropping to “E” (Edge) is peculiar because it implies the phone initially connects to the mobile network but then downgrades or loses the connection after a brief period.

Try switching between different network modes:

1. Go to Settings > Network & Internet > Mobile Network > Preferred Network Type.

2. Toggle between 4G (LTE), 5G, and 3G options to see if a particular mode works better.

3. SIM Card Test (Try a Different SIM)

If you have a spare SIM card lying around (or access to another one), try testing the Zenfone 10 with that card. This can help rule out whether it’s a SIM-specific issue or something deeper in the phone’s firmware.

• If another SIM works fine with mobile data, then it’s almost certainly related to a software or configuration issue with the T-Mobile SIM or the current update.

4. Revisit Factory Reset (Last Resort)

I know support recommended a factory reset, and I understand why you’d be hesitant given that it’s a major step. However, if you haven’t done it yet, it could resolve any deep software issues that aren’t cleared by basic troubleshooting. It’s a pain, but it’s worth considering if other options haven’t worked.

• Backup your data before proceeding! This will erase all personal settings, apps, and files.

• To factory reset: Go to Settings > System > Reset > Factory data reset.

This often clears up any configuration bugs that might have been caused by the update.

5. Check for a New Update

ASUS could be working on a bug fix for this, especially if it’s affecting many users after the same update. Keep an eye out for new firmware patches—either through Settings > System > Software Update or directly on the ASUS support page.

6. Contact ASUS Support Again

Since you’ve already contacted support, I recommend following up, especially since this seems like a widespread issue. Sometimes, issues like these need to be escalated to higher-level support teams, so report the problem as urgent.

Mention that:

• The problem appeared after the update (version 35.0604.0404.109).

• The device connects to the network but has no data, showing “E” instead of “4G/5G”.

• You’ve already tried all the usual troubleshooting steps (APN settings, resetting network settings, etc.), and the issue persists.

Request an official fix or timeline for when a patch might be available.