Just to elaborate more, I have deleted the 4 tags I am using in the SQL. I have indexed them again. I still have the same behavior. If I put the NOFILTER clause it's ok. If I don't, I have too many records in my SQL.

With the NOFILTER, I have 281 records. Without, I have 778 records.

So, as for a SQL, it's ok as I can force a NOFILTER and this solves the problem. However, for a COUNT I can't so I have the same behavior.