It's a problem I've had a few times and often the obvious advice does not work - that being rebooting, updating the firmware, changing DNS servers, parental controls, resetting to factory settings, etc. I've had issues with Waze not connecting through a Netgear Aircard hotspot, Echolink not connecting through neither my Huawei or Netgear hotspots, and an OpenSpot2 device not connecting through specifically my Huawei device. There is never an easy and quick answer as these issues can be quite complex but here are some ideas to help troubleshoot it:
- Try to ensure first that the issue is with the hotspot itself and do this by either using your phone's LTE or 3G directly or trying a different hotspot that a friend has. Or try to connect via your home WiFi.
- Check the app's network ports requirements as many use specific custom ports and not the usual port 80 or 443. Bear in mind an ISP that you use could also be blocking some ports so it may not always be your device. I've had this problem with the Echolink app that wants access via ports 5198 and 5199. In this case, you can see if your device has port forwarding where you can set those ports to forward but a challenge is it often wants to send to a specific local IP address and your phone's IP could change later if you have lots of other devices connecting. Another option is sometimes to activate a DMZ but again it is for a specific IP address and then essentially your phone has no firewall between it and the Internet (it's open) but it helps diagnose,
- Custom WiFi channels can also be checked for as the usual ones are channel 1 to 11 for 2.4GHz (the Channel that is open for local devices to connect to the hotspot) but many router hotspot devices will also extend up to channel 14 and if set to Auto, will utilise channels 12-14. Try setting the channel on the device otherwise to either 1, 6 or 11 instead of Auto. This helped me with Waze not connecting via a Netgear router hotspot device.
- A more tricky one is the actual security protocol used by the phone or other devices to connect to the WiFi on the hotspot. Today the norm is WPA2 (less easy to hack) but I've had a case with my Huawei E5885L that my OpenSpot2 device refused to connect properly with WPA2 and the only way it connected reliably was to change the WiFi security to WEP. This not desirable but I was not the only person affected with this specific Huawei device. Yet the same OpenSpot2 device connects OK with WPA2 on a Netgear device's WiFi.
- Try an Internet search for the specific service and the make and model of the hotspot as this is how I found the issue of the security protocol with the OpenSpot2 device - it seemed to be unique to this specific Huawei hotspot device.
- Try 2.4GHz WiFi specifically instead of auto-switch between 2.4 and 5GHz WiFi.
What makes mobile router hotspots more difficult to diagnose and fix is also the fact that they have fewer configuration options to work with versus their home router counterparts, especially with regard to assigning static IP addresses to connecting devices and firewall management.