ESP32 connects to Wi-Fi but can't access internet (NTP/MQTT fail)

[manchancleta]

Hello!

We have a custom board using an ESP32-WROOM-32D (it's a few years old) for IoT purposes. The ESP-IDF firmware connects to a Wi-Fi network, syncs time via NTP, sends some data via MQTT to a server, and then goes into deep sleep.

Everything works fine in my office and also when using my phone as a hotspot. However, I'm having trouble at a specific client site: although the ESP32 successfully connects to the router and gets assigned an IP address, it seems like it doesn't have internet access. It fails to reach the NTP server and, in the rare cases it does, it can't send data over MQTT.

Strangely, when I installed a Wi-Fi extender on the same network and connected the ESP32 to that instead, everything started working perfectly.

What could be causing this behavior, and how can I solve it? I suspect it might be related to the router configuration, but this client is small and doesn’t have an IT person, so I didn’t want to start changing settings without knowing what to look for. This is the first time I’ve encountered this issue.

Thanks in advance for your help!

[MicroController]

Strangely, when I installed a Wi-Fi extender on the same network and connected the ESP32 to that instead, everything started working perfectly.

Could be a plain old signal strength/RF interference issue...

[manchancleta]

Could be a plain old signal strength/RF interference issue...

I tested the ESP32 right next to the router and it still didn’t work, so I ruled out any signal strength issues. I only used the Wi-Fi range extender because I had it with me—and surprisingly, everything worked when connected to it.