Hi @LocalHeroPro and welcome to the community 
you already found the solution. the property sonar.embeddedDatabase.port defines the port for the embedded h2 database and not the postgresql that you want to attach sonarqube to. if you change the port, the h2 database will be created but sonarqube will fail to do something with it, resulting in the failure you observerd.
can you point us to the documentation that made you assume that you had to change this value, so we can improve our docs on this?
Thanks