Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:141.212.120.90.
Your query was changed from:
6add368da35458a09edf880d0570e863adc8507d49406b4d97e44e53bc9308c9
to
6add368da35458a09edf880d0570e863adc8507d49406b4d97e44e53bc9308c9
If this isn't what you intended, you can run your raw query without expansion.