Reinstalling your printer
If you still feel stuck and wonder why my computer says my printer is offline, then reinstalling it might be a better option for you.
Press Windows key + R to open a run box, and type devmgmt.msc in the box and press Ok.
Find the printer drivers under the print queue, and then right-click on it and choose uninstall device.
Download the latest printer driver from the manufacturer’s website, and install it to complete the process.
Disabling the ‘Use printer offline’ feature