As described, your Apple devices are very unlikely to have any bearing on the cause of your issue. The symptoms that you describe suggest that your WiFi Router may be unexpectedly failing to pass Apple Bonjour traffic between its 2.4GHz and 5Ghz network segments. Whether this is a fault, or Router configuration issue, can only be determined locally.
The Apple Bonjour protocol uses mDNS (Multicast DNS) UDP port 5353.
You may find that restart of your network components will resolve the problem. You’ll need to restart your network devices in the correct order. Assuming that you WiFi Router provides DNS services for your network, restart devices in this order - allowing time for devices to fully boot/restart prior to restarting other devices:
- WiFi Router
- Upstream wired Network Switch(es)
- WiFi Access Points / Network Extenders
- Other fixed infrastructure devices - such as Printers
- Client devices
Restarting your iPad, after restarting other devices in the correct sequence, is most simply achieved by a forced-restart of the iPad:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On an iPad with Face ID: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
If you are unable to identify a configuration issue with your WiFi Router, you would be well advised to substitute your router for a different model - or to add an additional WiFi Access Point with a different Network Name (SSID)via a wired Ethernet connection and use the additional network for your printer and Apple devices.
