Many thanks for your reply.
Whilst the version you named was not the correct version you did put me on the right track.
I ended up using the following MondoDB and Morphia dependencies in my pom
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongo-java-driver</artifactId>
<version>3.12.14</version>
</dependency>
<dependency>
<groupId>org.mongodb.morphia</groupId>
<artifactId>morphia</artifactId>
<version>1.3.2</version>
</dependency>
I’m listing these in case someone else might run into the same issue I ran into.