There are two possible solutions that I found for this issue:
The first one is to specify an exact version requirement, or "hard requirement" for a specific version of a dependency, as shown below:
<version>[1.5]</version>
instead of:
<version>1.5</version>
The second one is to use the mvn dependency:tree
Maven command to see exactly what dependencies are being pulled in, and in what hierarchy. In my case, this solved my problem when I noticed that one dependency was actually pulling in an older version of another dependency, as a sub-dependency. Despite the fact that the sub-dependency was specified on its own elsewhere in the POM, Maven used the older version that was pulled in as a sub-dependency. Sounds confusing I know, but either way, mvn dependency:tree
should show if a dependency is being pulled in unknowingly, or at an unspecified version.