I haven't made any changes to the survey settings, but recently iPhone users have not been able to use their device location when submitting a survey. Attached is a screenshot of the message received "Can not find your location. Please check your browser to ensure that your location is shared."

Can confirm it works on an Android device. Also the location services work on other Esri applications (e.g. WAB, ExB) using iPhone. We tested Safari and Chrome, and tried reseting caches - none of that worked. We also tested on two different iPhones, one with the latest OS update, and one with the previous version. Lastly we tested two different surveys, both have the same issue. Access them via these QR Codes:

Australian Protected Cropping Survey

Australian Tree Crop Survey