Github user JPercivall commented on the issue:
https://github.com/apache/nifi/pull/730
3 node secure cluster
process group in root group called test
have 3 processors in that group
1: one that inherits them all
2: one that was copied and pasted from the root group and has the "view
data" property overridden but no one added
3: one that overrides the inherited policy and added a user
copy those three processors from the test group to the root group
see 1 and 2 work fine. For 3, the overridden policy was removed entirely
see screenshot:

and where it was copied from:

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