iOS Mail S/MIME cert installed and trusted but “No valid certificates found”
Seems like I have similar problem as described in iOS Mail S/MIME cert installed and truste… - Apple Community. Thread is closed (due to no activity) so I'm starting new one.
I've just purchased S/MIME certificate. It took me < 5 minutes from purchasing it to having Mail working properly in macOS (signing + encrypting). I spend next 5 hours trying to make it work in iOS.
I exported certificate from Keychain Access to p12 file, installed it in iOS (along with intermediate certificate).
In General->VPN & Device Management certificate is "green" (Verified), but in Me->iCloud->iCloud Mail -> iCloud Email Settings -> Advanced -> Sign/Encrypt certificate is "red" (Not Verified).
Mail app shows e-mail sent from macOS as signed and encrypts it properly, but when trying to send e-mail, popup message shows "Unable to encrypt" and sends me to Settings, even though certificate _is_ selected (with checkmark) in Advanced Mail settings.
I managed to configure S/MIME in iOS many times in the past when using previous major versions of iOS. It's just me (or certificate provider) or is it a bug in 16.x version? It works properly in macOS, so it should in iOS as well?
iPhone 8, iOS 16