I have an app written that has been working for over 3 years. The app is installed via OTA. Was contacted by user yesterday with an iPad Air 3rd generation with ipados 13.3 and the app will not install on his device. It says the certificate is not valid. This is the first time in over 3 years we have had an issue where the app will not install on a device. It appears to correctly install on any other ipad (have not had any calls) but outside the ipad air 3 there, all the other ipads were released in 2018. Did apple change something with the new ipads that come out in 2019 to use a different certificate type causing the install to fail?
