When an airgroup is created for a printer, that individual may not be able to print and the printer may appear as offline.
The computer tries to connect to the printer through its old path and when it can't find the device it shows as offline. You need to remove the printer with the previous path and re-add it
(Windows 10) If this happens have them go to Control Panel -> Hardware and Sound -> Devices and Printers
Click on the printer causing the trouble
Remove device (Top menu bar)
Add a printer
Re-add the original printer
May also need to add the printer via IP