AirPort Express 1st gen keeps disconnecting

Both the 1st and 2nd generation 802.11n AirPort Express base stations support AirPlay. However, only the 2nd generation model, with firmware version 7.8 or later, can support AirPlay 2. Regardless, both base station would need to be configured to join the wireless network provided by your Netgear Nighthawk wireless router.

This is where the location of each of the base stations will be critical in order for each of them to receive a strong enough signal from the Nighthawk to connect, stay connected, and handle the AirPlay stream. In addition, the location of the device that is streaming will be important. That is because, the stream must first travel from this device to the Nighthawk, and then, travel to either or both Express base stations. Anything, like walls, between them could cause Wi-Fi interference and either the loss of a streaming connection or affect the overall streaming quality performance.

The key is to measure the Signal-to-Noise Ratio (SNR) of the Netgear's wireless network at the location of each of the Express base stations. To do so, check out the following user tip article. Although is was intended to cover extending a wireless network, it will equally apply here as far as making the SNR measurements.

Ref: AirPort - Optimal Base Station Placement - Apple Community

To downgrade the AirPort's firmware:

• Open AirPort Utility.
• Select the base station, and then, click on Edit.
• A new window will appear. Hold down the Option key and hover the mouse cursor over the firmware build number. The firmware version number should now be highlighted.
• While still holding down the Option key, click on highlighted number to see all the firmware versions that are available.

• Click on the one you want to downgrade to.
• A dialog box will pop-up to let you know that the base station will be unavailable during the downgrade process.
• Choose either "Continue" to continue with the downgrade OR choose "Cancel" if you decide not to.
• If you choose to continue, allow the firmware to be downloaded, installed, and for the base station to restart.

-- credit: Bob Timmons

The 7.8.x firmware version is known to be problematic. I suggest that you downgrade both of your Express base stations to 7.6.9 or 7.6.8 for AirPlay consistency. You will lose AirPlay 2 capability on the 2nd gen Express, but both should now have AirPlay 1 functionality. Note: The 1st gen 802.11n Express is not AirPlay 2 compatible.

You're very welcome!