Changed Router Now Wifi won't connect

    Hi, I've been using a RapsberryPi 3 with LibreElec sucessfully for ages. My router started acting up, so I replaced it today. Both routers were Linksys WRT series models and both have exactly the same settings. All my devices work except for the LE one. On that, I get the wifi swapping between associating and idle. It just won't connect.

    I made a brand new sd card and installed that. If I connect via an ethernet cable, then I can ssh in, use connmanctl, agent, scan wifi, services, connect {WIFI NAME}. That worked. Then I disabled the wired network, edited the Wifi connection and told it to connect automatically, then told it to reboot, and then I'm straight into the same associating - idle - associating - idle loop and it doesn't connect.

    I've tried changing the Wifi channel to 10. I've tried explicitly setting my country to GB.

    I'm at a loss. As far as I can see the router settings are the same on the new router as the old one (it is a newer model though). ALL my other devices work perfectly.

    Any ideas? I can only connect to a cable while setting it up. Its usual location has no cables.

    It's similar to this problem : RPI4 Network Error: Input/Output Error for wireless

    I tried looking at the logs but couldn't find any errors. I not managed to copy one as frequently once it gets stuck in this loop, it sometimes reboots after I enable the wired network.

    Where would I look in the logs for network errors.

    Incidentally, my original SD card won't do the connmanctl sequence. It doesn't ask for a password at the connect stage, it just displays an error and won't continue.

    Help please!

    Quote from WhyWontItWork

    I can only connect to a cable while setting it up. Its usual location has no cables.

    Have you tried connecting across WiFi when your RPI3 is directly in front of the Router? Maybe the signal is not strong enough in "usual location".

    Another possibility could have something to do with the Firewall settings and/or DHCP dynamically assigning new IP to your RPI3 after each reboot.

    Can you try and disable firewall on RPI3?

    Yes it was directly in front of the router - it had to be because I had to run a short cable from the router to connect by cable temporarily. Firewalls hadn't changed, but tried it without - no difference :-(. I experimented with DHCP & assigning addresses. No joy.

    So....

    I had a Pi 3b+ doing another job, and I swapped the brand new LE card into it - connected to the network 1st time. I tried the original LE card in it. Connected to the network 1st time.

    I thought then it must be a the original pi 3b must have got a fault. I swapped the machine that was doing Libreelec into the job the other pi was doing, and it worked 1st time with no changes.

    Grasping at straws, I wonder if the "bios" of the pi 3b that I was having problems with LE with, was not as up to date and couldn't cope with something the router was doing.

    Whatever - it now works.

    Case closed.