If you don't know what you are voting for then the motion as presented is flawed and should be challenged.
Using a 'blanket' exclusion of the press and public is inappropriate just because it is 'staffing issues.'
Some staffing issues (performance for example) might warrant exclusion but not all (tasking, pay rates, priorities etc.) You were quite right to challenge the motion if you didn't know what the reason was.
Also, if you end up in a closed session and items that are NOT qualifying subjects for exclusion of the press and public are covered, you should raise a point of order and highlight the impropriety.