Spring Boot/Thymeleaf Executable Jar, Cannot find template location: classpath:/templates/ - spring

Question

I've built an Restful API using Spring Boot and I'm deploying it as an executable Jar file using Maven. Build section of my POM file as follows;
<build>
<finalName>project-name</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
I've added Thymeleaf to my project as I need to display a HTML file. I have not added any additional configuration options to my application.properties file. I have created a simple HTML file in the folder '/src/main/resources/templates/' and I've created a controller to display the HTML file.
If I run the project within IntelliJ, I am able to view the HTML file via the controller.
If I run the project using 'mvn spring-boot:run', I am able to view the HTML file. via the controller.
However I am not able to view the HTML file when the project is ran from the executable Jar file that maven creates after I've ran 'mvn package'.
When the project is ran from the executable jar, I see the following output upon startup;
18:18:38.234 [main] WARN o.s.b.a.t.AbstractTemplateResolverConfiguration - Cannot find template location: classpath:/templates/ (please add some templates or check your Thymeleaf configuration)
I'm assuming from this that it's unable to locate the /templates/ folder. In an effort to debug the issue I extracted the executable jar and I see the following folder structure;
- BOOT-INF
- classes
- templates
- mails
reset.html
password-reset.html
- lib
- META-INF
- org
I can clearly see that the templates folder is in the jar along with the HTML file 'password-reset.html'.
I seem to be having a similar issue with another part of the project too, which loads the contents of a file into a string. The code below again works fine ran from IntelliJ and when running via 'mvn spring-boot:run', but it's not able to load the file when ran from the executable jar.
Resource resource = new ClassPathResource("templates/mails/reset.html");
BufferedReader br = new BufferedReader(new InputStreamReader(resource.getInputStream()), 1024);
StringBuilder stringBuilder = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
stringBuilder.append(line).append('\n');
}
br.close();
body = stringBuilder.toString();
I'm guessing there is some issue with the classpath(?) in the project when it's ran from an executable jar. I wonder if anyone has any idea why I'm experiencing this issue and what I can potentially do to resolve it?