In 1.12.2, when water source or flowing blocks were above mycelium, and the light level was reduced below 4, mycelium blocks would turn to dirt blocks randomly. However, with the release of 1.13, this behavior is no longer present. It appears that it cannot spread, but it will not die either.
Environment
OS: Windows 10 Home 64 bit
Java Version/Info:
java version "1.8.0_144"
Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)
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However, this issue is a Duplicate of MC-130137.
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