Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:18.104.22.168.
Your query was changed from:
parsed.tbs_noct_fingerprint: 19c650f8b989a2a8b49b5d06a003b0375dbf5c6597aa83af3714a3953818ff8d and precert: true
parsed.tbs_noct_fingerprint: 19c650f8b989a2a8b49b5d06a003b0375dbf5c6597aa83af3714a3953818ff8d AND precert: true
If this isn't what you intended, you can run your raw query without expansion.