Hi. 2 month since I switched from z5 to z7. Bought from the same official Samsung store. Nothing changed, same WiFi, same carrier, same apps, same settings, latest updates. Constantly adguard in use (nothing changed there also). Since last week, this week even 2 days in a row, internet started suddenly disappearing. Like phone network chip was turned off completely. Internet over WiFi is not working, over carrier not working (tried SIM on other phone - works) unless I reboot my phone. I haven't found yet how to replicate the issue, it just randomly disappear. Browser say "DNS error, diagnosing issue"., Nothing over internet. Someone else faced the same issue?
Thank you for contacting us and sharing your concern.
Please follow the troubleshooting steps below to resolve the problem. After completing all steps, check whether the issue has been resolved or if it still exists.
Advanced Troubleshooting Steps:
Since you have confirmed that your carrier and Wi-Fi work on other devices, focus on these phone-specific solutions:
Wipe Cache Partition This often resolves connectivity glitches caused by corrupted temporary files after a major OS update:
Turn off your Z7 phone.
Connect your phone to a computer using a USB cable.
Press and hold the Volume Up and Power keys simultaneously until the Samsung logo appears, then release.
Use the Volume Down key to navigate to “Wipe cache partition” and press the Power key to select it.
Select “Yes” and then “Reboot system now.”
Reset Network Settings This will erase all saved Wi-Fi networks and Bluetooth pairings, giving your connectivity settings a clean slate:
Go to Settings > General management > Reset > Reset network settings.
Tap Reset settings and confirm with your PIN if required.
Check AdGuard DNS Settings Since you use AdGuard, verify its settings. The “DNS error” message suggests a DNS failure, possibly due to an update conflicting with how AdGuard manages private DNS:
Open AdGuard and check its advanced settings.
Temporarily disable AdGuard to see if the issue stops.
If the problem occurs only when AdGuard is enabled, it is likely an app-specific conflict. AdGuard may need to release an update to resolve this.
Boot into Safe Mode This will determine if another third-party app (other than AdGuard) is causing the issue:
If the internet works fine in Safe Mode, a conflicting app may be causing the problem.
Change MAC Address Type Some users have resolved Wi-Fi issues by changing this setting:
Go to Settings > Connections > Wi-Fi.
Tap the gear icon next to your network name.
Tap View more or Advanced.
Under MAC Address Type, change it from “Randomized MAC” to “Phone MAC.”
