It might be possible that you were charged with a felony and convicted of a misdemeanor. Or, you had been entered into a diversion program that resulted in the offense being dropped to a misd. or dismissed upon successful completion of probation.

If you had a background check done and have been permitted to possess a firearm at work, then you do not have a felony conviction. Or, MO has very, very, VERY poor criminal offender background system.