Since LLC's are registered at the state level, I know in FL you are required by the state to always include either the letters LLC or the words "Limited Liability Company" in all paperwork and advertising that relates to the business.
Now assuming you applied for an EIN with the IRS and you did not enter "LLC" on your application with the IRS, your state has nothing what-so-ever to do with your error. But there is a procedure for changing the name with the IRS and retaining that same EIN. See https://www.irs.gov/businesses/business-name-change for details.
