When using "count" I have found that less frequent counts in a query are often incorrect. My ad hoc workaround has been to always set limit to 999, and only use the first 100 counts. For example,
the following query
indicates there are 13428 reports with patient.reaction.reactionmeddrapt.exact=NEUTROPENIA.
indicates there are 26220 such reports.
Interestingly, this (with ... replaced by text in previous links):
also indicates there are 26220 reports.
Is this a bug, or am I missing something?