DIAGNOSIS The printer is powered on and connected to the network, but its status is not being communicated correctly to your computer. The most common cause is a stalled print job or a temporary communication glitch in the driver.
FIX First, clear all pending print jobs. Open your computer's Printers & Scanners settings. Right-click the HP OfficeJet Pro 9125e and select 'See what's printing'. Cancel all documents in the queue. Next, restart the communication cycle. Turn the printer off using the power button. Unplug the power cord from the printer for 60 seconds. Plug it back in and power on. Finally, on your computer, right-click the printer again and select 'Troubleshoot'. Let Windows run its diagnostic.
IF THAT DIDN'T WORK The issue may be a corrupted driver. In Windows Printers & Scanners, remove the 9125e. Then reinstall it using the 'HP Smart' app from the Microsoft Store. Do not use a USB cable during setup; let the app discover it on the network.
HEADS UP If the printer's front panel shows a solid blue 'Wi-Fi' icon, its network connection is stable. The 'offline' status is almost always a computer-side driver or queue problem, not a printer hardware fault.