

The only solution would be to stop using Java SSL enceryption and convert the entire plugin to native C/C++, and then call my own copy of OpenSSL. The Pixel phones are not officially sold in Switzerland, and I'm not willing to pay $1000 for a phone which will not get any more updates in one year (Google released it in October 2017, and offers 2 years of platform updates). The error does not occur in the emulator.

I cannot even check whether the structures were hidden or just renamed, because I don't have any Android 9 device. Java does NOT officially support SSL session reuse, so I have to access some internal structures to make it work. Unfortunately there is very little hope to make this work: Google is hiding more and more undocumented functions from Java, and doesn't provide any official replacements.
