UL illustrated inconsistent report wrt heap usage.

An example:
[137.848s][trace ][gc,heap ] GC(203) Heap after GC invocations=199 (full 6):
[137.848s][trace ][gc,heap ] GC(203) garbage-first heap total 52428800K, used 32747489K [0x00007f6648000000, 0x00007f6648164000, 0x00007f72c8000000)
[137.848s][trace ][gc,heap ] GC(203) region size 1024K, 640 young (655360K), 640 survivors (655360K)
[137.848s][trace ][gc,heap ] GC(203) Metaspace used 8554K, capacity 8993K, committed 9216K, reserved 10240K
[137.848s][info ][gc ] GC(203) Pause Young (G1 Evacuation Pause) 31983M->31979M(51200M) (137.533s, 137.848s) 314.886ms
[137.848s][info ][gc,cpu ] GC(203) User=4.60s Sys=0.02s Real=0.31s
[137.867s][trace ][gc,heap ] GC(204) Heap before GC invocations=199 (full 6):
[137.867s][trace ][gc,heap ] GC(204) garbage-first heap total 52428800K, used 32847841K [0x00007f6648000000, 0x00007f6648164000, 0x00007f72c8000000)
[137.867s][trace ][gc,heap ] GC(204) region size 1024K, 739 young (756736K), 640 survivors (655360K)
[137.867s][trace ][gc,heap ] GC(204) Metaspace used 8554K, capacity 8993K, committed 9216K, reserved 10240K
[137.867s][info ][gc,start ] GC(204) Pause Full (System.gc()) (137.867s)
[153.636s][info ][gc ] GC(204) Pause Full (System.gc()) 32078M->30089M(51200M) (137.867s, 153.636s) 15768.953ms
[153.636s][info ][gc,heap ] GC(204) Eden: 101376K->0K(5242880K)
[153.636s][info ][gc,heap ] GC(204) Survivor: 655360K->0K(655360K)
[153.636s][info ][gc,heap ] GC(204) Old: 32093184K->32848896K
[153.636s][info ][gc,heap ] GC(204) Humongous: 0K->0K
[153.636s][info ][gc,metaspace] GC(204) Metaspace: 8554K->8554K(10240K)
[153.636s][trace ][gc,heap ] GC(204) Heap after GC invocations=200 (full 7):
[153.636s][trace ][gc,heap ] GC(204) garbage-first heap total 52428800K, used 30811335K [0x00007f6648000000, 0x00007f6648164000, 0x00007f72c8000000)
[153.636s][trace ][gc,heap ] GC(204) region size 1024K, 0 young (0K), 0 survivors (0K)
[153.636s][trace ][gc,heap ] GC(204) Metaspace used 8554K, capacity 8993K, committed 9216K, reserved 10240K
[153.636s][info ][gc,cpu ] GC(204) User=28.50s Sys=0.01s Real=15.77s
[154.552s][trace ][gc,heap ] GC(205) Heap before GC invocations=200 (full 7):
[154.552s][trace ][gc,heap ] GC(205) garbage-first heap total 52428800K, used 36054215K [0x00007f6648000000, 0x00007f6648164000, 0x00007f72c8000000)
[154.552s][trace ][gc,heap ] GC(205) region size 1024K, 5120 young (5242880K), 0 survivors (0K)
[154.552s][trace ][gc,heap ] GC(205) Metaspace used 8554K, capacity 8993K, committed 9216K, reserved 10240K