Im having to switch from connected wifi to my printer just to print something and then switch back to wifi.

Hi,

Is the printer connected by USB to the Mac?

Or, just guessing here, is it somehow possible that you have set the ET-2800 printer to work in a Wi-Fi Direct Mode (see page 36 in the https://files.support.epson.com/docid/cpd6/cpd60271.pdf user's guide)? The Mac computer would then have to directly connect wirelessly to a built-in access point in the printer each time you want to print, instead of using its normal wireless connection to a Wi-Fi router.

Wi-Fi Infrastructure Mode (page 33 in the same user's guide) should be used for both the Mac computer and the printer. That is, the Mac and the printer should be connected to your normal Wi-Fi router. Printing would then be done via the router.

The Epson ET-2800 is listed in About AirPrint - Apple Support as a model supporting Apple's AirPrint technology. Provided that the printer and the Mac are connected to the same network (Wi-Fi router), no additional printer drivers should be needed.

Add a printer to your printer list so you can use it on Mac – Apple Support (UK)

We have several wireless printers and all work without interrupting internet connections. I've never seen one do as you describe.

Unless the wireless printer uses the same frequency as wi-fi this should not happen. And that should not be the case.

Devices must certify to the FCC (in the US at least) that their devices will not cause interference. I suspect your printer is either defective or somehow improperly set up. But. that is strictly a guess.

Can you use the printer in wired configuration? If so, try that a retest for the condition.

You ISP has no effect on your local network other than to provide a signal.

Is this a new problem? If so, what changed?