DIAGNOSIS The printer's initial Wi-Fi setup can be fussy, especially with modern dual-band routers that use the same name for 2.4GHz and 5GHz networks. The 9015e needs a 2.4GHz connection.
FIX Skip the wireless setup on the printer's touchscreen for now. On your computer that's connected to your Wi-Fi, download and run the full 'HP Smart' app from hp.com. When it prompts you to set up a new printer, connect the printer to your computer directly using a USB cable. The app will guide you through the rest and push the correct Wi-Fi settings to the printer over the USB connection.
IF THAT DIDN'T WORK Your router might be blocking the connection. Temporarily disable any advanced features like 'AP Isolation' or 'Client Isolation' in your router's settings. Also, try moving the printer closer to the router during setup, as physical obstructions can cause the initial handshake to fail.
HEADS UP Don't waste time typing a complicated Wi-Fi password on the tiny touchscreen. The USB method via the HP Smart app is almost always faster and more reliable for getting this model online the first time.