LG G4 ignoring a 5 GHz Wifi hotspot

Problem: My LG G4 (Android 5.1, kernel 3.10.49) suddenly ignored my home’s 5 GHz router. It saw the neighbors’ networks all right, but not mine.

Reason for problem: I had activated the phone’s hotspot previously. It seems like that locked the Wifi hardware to the 2.4 GHz band, as it happens to transmit on 2.437 GHz (channel 6). Correction: It seems like the phone doesn’t detect the 5 GHz hotspot if it wasn’t present on boot. Regardless of hotspot activation.

Solution: Reboot the phone. As simple as that. That is, restart Android, with the 5 GHz hotspot present and with Wifi enabled on the phone (before rebooting or enabled soon after boot). Turning the phone off and on again would probably do the same job, but why bother. It has been suggested to turn flight mode on and off, but that didn’t work for me.

Conclusion: Treat your smartphone for what it is: A small, weak and expensive computer with a lot of silly bugs.

Update (Jun 2017): After changing to another 5 GHz channel, the phone detects the hotspot normally. It seems like the previous 5 GHz channel I used wasn’t an allowed frequency in Israel, so the phone ignored it (and sometimes didn’t). Or maybe there’s also some kind of software upgrade that has taken place since.

By the way, I tried to move the G4′s hotspot to 2.452 GHz (channel 9) in the Advanced Settings, but the reception signal on the laptop went down. Go figure.