Security warning for Epson ET-2850 printer after iOS 18.5 update on iPhone 11

Many home and small office printers, like your Epson ET-2850, generate their own "self-signed" security certificates for encrypted communication (like AirPrint). These certificates are not issued by a trusted third-party authority (like VeriSign), so your iPhone's more rigorous security checks in iOS 18.5 see them as "untrusted."

Even if it's the same physical printer, if its network configuration changes (e.g., after a router restart, a printer firmware update, or even just powering it off and on), it might generate a new self-signed certificate, making it appear "different" to your iPhone's saved connection profile. Your laptop doesn't care about this in the same way, which is why it still prints fine.

What to do to resolve the issue:

1. "Trust" the Printer (if the option appears): When you get the security warning, there might be an option to "Trust" the printer or "Continue" anyway. If you're confident it's your printer and you're on your private home network, selecting this option should allow you to print. The warning might reappear if the printer's certificate changes again.
2. Restart Everything: This is often a surprisingly effective first step:
   1. Restart your Wi-Fi Router: Unplug it for 30 seconds, then plug it back in and wait for it to fully boot up.
   2. Restart your Epson ET-2850: Turn it off completely, wait a minute, and then turn it back on.
   3. Restart your iPhone 11: Power it off and then back on.
3. Forget the Printer on your iPhone:
   1. Go to Settings > Wi-Fi on your iPhone.
   2. Tap the "i" icon next to your Wi-Fi network.
   3. Scroll down and look for "Configure IP" or "DNS". Make sure it's set to "Automatic" or DHCP.
   4. (Less likely to be directly printer-related, but worth checking) Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. Be aware this will clear all saved Wi-Fi passwords on your iPhone. You'll have to re-enter your Wi-Fi password.
   5. Go to Settings > General > AirPrint > Printers (or similar, depending on iOS version). See if you can "forget" or remove the Epson printer from this list. If not, the previous network reset might help.
4. Check for Printer Firmware Updates:
   1. Go to Epson's support website for the ET-2850.
   2. Look for the latest firmware updates. Sometimes, printer manufacturers release updates to improve compatibility with new operating systems. Follow Epson's instructions carefully to update the firmware.
5. Use the Epson Smart Panel App:
   1. If you haven't already, download the Epson Smart Panel app from the App Store.
   2. This app often provides a more robust and direct connection method to your printer and might bypass some of the iOS AirPrint security checks. It also allows for easier printer setup and troubleshooting.
6. Disable "Private Wi-Fi Address" (if applicable):
   1. While usually not the primary cause for printer issues, for your home network, the "Private Wi-Fi Address" feature (introduced for privacy on public networks) can sometimes interfere with local network device discovery.
   2. Go to Settings > Wi-Fi on your iPhone.
   3. Tap the "i" icon next to your home Wi-Fi network.
   4. Toggle off Private Wi-Fi Address. Test printing again. You can re-enable it if it doesn't help.

I am experiencing the same issue today. Did you ever find a solution? This is crazy. I really like this printer but why should I spend $$ on a new printer when this must be some kind of glitch. Mine worked with the IOS 18.5 update on iPhone 13 until I updated the firmware on the ET-2850 today.