java8 compiler fails to compile

[umjammer]

[INFO] -------------------------------------------------------------
Error:  COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
Error:  /home/runner/work/vavi-nio-file-discutils/vavi-nio-file-discutils/src/main/java/DiscUtils/Streams/StreamExtent.java:[112,16] reference to union is ambiguous
  both method union(DiscUtils.Streams.StreamExtent[]...) in DiscUtils.Streams.StreamExtent and method union(java.util.List<DiscUtils.Streams.StreamExtent>...) in DiscUtils.Streams.StreamExtent match
Error:  /home/runner/work/vavi-nio-file-discutils/vavi-nio-file-discutils/src/main/java/DiscUtils/Streams/StreamExtent.java:[112,72] incompatible types: inferred type does not conform to upper bound(s)
    inferred: java.util.List
    upper bound(s): DiscUtils.Streams.StreamExtent[],java.lang.Object
Error:  /home/runner/work/vavi-nio-file-discutils/vavi-nio-file-discutils/src/main/java/DiscUtils/Streams/StreamExtent.java:[208,16] reference to intersect is ambiguous
  both method intersect(DiscUtils.Streams.StreamExtent[]...) in DiscUtils.Streams.StreamExtent and method intersect(java.util.List<DiscUtils.Streams.StreamExtent>...) in DiscUtils.Streams.StreamExtent match
Error:  /home/runner/work/vavi-nio-file-discutils/vavi-nio-file-discutils/src/main/java/DiscUtils/Streams/StreamExtent.java:[208,76] incompatible types: inferred type does not conform to upper bound(s)
    inferred: java.util.List
    upper bound(s): DiscUtils.Streams.StreamExtent[],java.lang.Object
[INFO] 4 errors 

java13 is ok