iPhone Xs occasionally loses internet connection and requires reboot

NamVet69-70 wrote:

My wife's iPhone Xs occasionally shows "no internet connection". Sometimes it will automatically clear and other times it requires a reboot. Either way it also has issues until it clears. We have two iPhones, hers and mine which is an X, an iMac 27", an iPad Mini 5th gen, and a MacBook Air 13" M4. None of the other devices ever show a problem. Looking over all the setting on everything there is nothing glaringly wrong. I know it's got to be something simple or stupid but I'm at a loss. The router is a TP Link 5260.

The reality is you have an iPhone from 2018 and it may be showing the signs of a Wifi radio hardware failure. I'd schedule an appointment at your Apple Store Genius Bar to have the phone tested --> Genius Bar Reservation and Apple Support Options - Apple

If there is a hardware issue, it would not make sense to spend any money on an 8 year old iPhone.

With that number of devices I would try setting your router to broadcast a 5Ghz only frequency instead of the multiband 2.4Ghz/5Ghz frequency, and connecting your devices to that 5Ghz only Wifi Network. The 2.4Ghz band is only there for compatibility with older devices, none of which include any of those mentioned in your post. This frequency suffers from band overlap and interference when multiple devices are involved and it is not unusual to see those affects on only one device.

It certainly may be another issue with the device, but creating a 5Ghz only network is easy to do for testing if that will resolve your problem. On the TP-Link router you may need to disable its Smart Connect/Band Steering feature before you can choose only 5Ghz. Once you create that Wifi Network, connect your devices to it. If you want to maintain both networks on your router, just disable Auto-Join on your devices for that multi band WiFi network and Auto Join the 5Ghz one instead.