Why will an older device connect to 2.4 GHz Wi-Fi but not my current network?

First separate two questions: which Wi-Fi bands the device supports, and whether its setup process works with your current network configuration. Compatibility varies by exact product: some devices support only 2.4 GHz, while others can use 2.4 or 5 GHz. “Older” alone doesn’t tell us which applies. [S1]

Find the device’s model number and check its manufacturer’s specifications and setup instructions. Look for supported bands and any stated network requirements. A network name appearing on your phone does not prove that the device supports the same connection.

Not necessarily. A single displayed network name doesn’t establish which band the device is using or whether its setup will work. Follow the maker’s instructions for your exact model before changing router settings.

For example, if the manual says the device requires 2.4 GHz, note that requirement and check—using the router or device maker’s instructions—which band is being used during setup. If the manual doesn’t specify a band, don’t guess: record the model and ask the maker. This is a way to organize the check, not a claim that a particular router setup will work.

Also write down the network name, the screen or step where setup stops, and the exact error message, if any. Changing one thing at a time makes it easier to tell what affected the result.

It can matter in some setup situations. Google says most routers allow devices on 2.4 GHz and 5 GHz to communicate across bands, but some problems in the Google setup scenario may call for temporarily connecting both the relevant device and the setup phone to 2.4 GHz. That is conditional guidance, not a universal instruction for every device or router. [S2]

If your device maker’s instructions point to this kind of issue, check whether the phone and device are on the required band during setup. If you can’t tell how to check on your equipment, ask the device maker or router provider rather than guessing at settings.

Check the manufacturer’s setup guidance and note exactly where the process stops. Google identifies access-point isolation as one possible communication barrier in its setup scenario. That does not prove isolation is enabled on your router or is causing your problem. [S2] Before changing isolation or another router setting, confirm that the device maker’s instructions call for it and ask the router provider how to check safely.

Use this checklist:

• Device model and router model, if known.
• Setup phone model.
• Device-supported band(s), according to its instructions, or “not confirmed.”
• Network name and band used during setup, if known.
• The step where setup stops and the exact error message, if any.
• Changes already tried, with the result of each.

Ask: “Does this exact device require a 2.4 GHz connection or another network setting for setup? Could a router setting prevent the phone and device from communicating? Which setting should I check, and how do I restore it afterward?” Keep the answer specific to your models; the supplied guidance does not establish one configuration or fix for every device.