Can no longer air print to my Canon Pixma TR8520

My iPhone XS Max and my iPad were air printing just fine to my Canon Pixma TR8520 until yesterday. The only thing different is that I set up an older PC to print wirelessly as well (I downloaded Canon software to the PC). The PC and our Dell laptop print fine, but not my Apple devices. The Apple devices can see the printer but when I hit Print an error message says Printer Offline. I’ve spoken to technicians at Geeksquad and Canon to no avail.

I’ve already tried powering off the devices, the printer and the router. Please help!