Spring-Boot-Tests not running in eclipse

I have a project with a load of spring-boot-tests that run fine when I do a mvn build, but always fail almost immediately when i run them from eclipse.

The tests from a different project, that are very similarily structured, run fine in Eclipse.

I´m not sure if it´s relevant, but for some reason src/test/java and src/test/resource are located before src/main/java and src/main/resource in the package explorer view for that project and I can't find out why or how to change it.

The exceptions are usually very plain:

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class nested exception is org.springframework.context.annotation.ConflictingBeanDefinitionException: Annotation-specified bean name 'swaggerConfig' for bean class conflicts with existing, non-compatible bean definition of same name and class

Or something similar.

Any ideas of why Eclipse is messing with me?

Edit: using Version: 2018-12 (4.10.0)