In the current open bi Respository Server releases 3.0.0.x and 3.0.1.x there is a bug with the automatic https certificate installation.
If the you want to change the certificate, the open bi Repository Server does not automatically uninstall the previous certificate.
The workaround is to uninstall the previous certificate manually by executing the following statements in an elevated command prompt:
netsh http delete sslcert ipport=0.0.0.0:9092 netsh http delete sslcert ipport=[::]:9092
After that you can restart the open bi Repository Server and the new certificate is installed correctly.
The bug is fixed with the upcoming 3.0.2.x release.