Limitations ?

Hello,
Been beating my head against the wall all day and am leaning towards the issue might be an aspect of the MySQLi behavior.

Problem:
I have a MySQLi recordset that should be pulling 29 records but is only showing three. The three is only the records from the first value in an IN () statement.

I've attached the file with comments and will outline what it does in the following steps:

1) Select a Member ID and put it in an array
2) Using a recordset query , poll the DB for any candidates to add to the array
3) Implode the array to have individual values comma separated and reset to the var
4) use that variable in a MySQLi recordset
5) use debugSQL() to see results of final query

Results are:
SELECT tblinventory.invId FROM tblinventory WHERE tblinventory.mid IN ('11','10','20') AND tblinventory.invReleased = 0 ORDER BY rand()

If tested in PHPmyAdmin , 29 records are returned that is accurate for the three values in the IN selector
BUT as a result of the MySQLi recordset behavior only the 1st value in the IN selection is used so only 3 records are the result.

Why is this?