Mac mini m1 doesn't auto connect 5Ghz wifi after reboot

Connect to that 5Ghz SSID name, and then launch System Preferences > Network panel. Ensure that the specific network name appears in the Network Name selector, and select Automatically join this network. Click the Apply… button if available, and then quit System Preferences. Reboot, and see if the M1 mini gets it right the first try.

This appears to me, as Router Configuration issue.

Log into the Router and you will have to find the setting that controls the Wifi setting.

In there, there probably is a Setting specific controlling the 5 ghz Broadcast Signal.

Verify if the 5 ghz signal is set to " Auto " or is set to Only " ac " signal

For bester results suggest setting it to Auto.

This will allow the Router to broadcast the 5 ghz signal in the g, n and ac depending on the request from the connecting device.

In this case the M1 Mac Mini

For good measure - restart the Router and Test the problematic computer from a cold boot.

refer to image below

Hello anthonyphung,

Just to confirm, does this occur with all Wi-Fi networks, or just that specific one?

Is your network using the recommended settings for Wi-Fi routers and access points, as outlined in this link? Recommended settings for Wi-Fi routers and access points

If your Mac isn't connecting to Wi-Fi as expected, please check out this link for some steps that can help with Wi-Fi connection issues: If you can’t connect to a Wi-Fi network on Mac

• Make sure Wi-Fi is turned on. You can use the Wi-Fi status icon  in the menu bar to turn Wi-Fi on.

• You may be out of range. Make sure your Mac is within range of the wireless network.

• The Wi-Fi service may not be available in Network preferences.

On your Mac, choose Apple menu  > System Preferences, then click Network .

If Wi-Fi isn’t in the list of network connection services, click the Add button  at the bottom of the list, click the Interface pop-up menu, then choose Wi-Fi. Name the Wi-Fi service, then click Create.

• If you are connecting to a wireless network created by an AirPort base station or AirPort Time Capsule, restart the device by unplugging the power cord. Wait a few minutes, then plug the power cord back in. After the network is available, try connecting again.

Thanks!

Then just use 2.4. Or give them both the same SSID name. Recommended settings for Wi-Fi routers and access points – Apple Support (AU)

If the Router has both 2.4 and 5 ghz and broadcasting the Same SSID with the same Wifi Password - the strength of the signal that is strongest will probably be the one it connects to first.

I find for best and reliable connection to the 5 ghz Wifi is keeping the computer in a direct line of sight. That being no walls or the construction between the Wifi Signal and Computer work best.

Otherwise, the 2.4 ghz signal, which is better for penetrating obstructions will be the better of the two