Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:126.96.36.199.
Your query was changed from:
parsed.names: (dns_names or *.cloud.zoom.us)
parsed.names: (dns_names OR *.cloud.zoom.us)
If this isn't what you intended, you can run your raw query without expansion.