There is a java library dependency in Janusgraph "high-scale-lib" which is old and unsupported library(last update happened 8 years back, see https://github.com/boundary/high-scale-lib). When Janusgraph is included as library into another project it causes IDE issues when loaded into Eclipse or VScode and using Java 11, just because it contains packages like "java.*"

As a solution I would suggest to migrate to a successor project which is actively developed https://github.com/JCTools/JCTools and does not have such issues