Valid S/MIME certificates are displayed as invalid with a question mark since iOS 15.2.

I have purchased a S/MIME certificate from sectigo in Nov 2021. This worked perfectly until the update to iOS 15.2. After that my certificate has a question mark for me and all my recipients in iOS 15.2 but in Outlook or other programs everything is fine.

After that i purchased a new certificate on 17/DEC/2021 from Globalsign. This one have also this red question mark. But if I go to the certificate also by the recipients then the certificate is displayed as valid.

I immediately tried this problem on my iPhone 5S with iOS 12 and there is my certificate blue and valid.

What happened here with iOS 15.2 that sectigo and Globalsign certificates are showed with a red question mark?