One of my employers used my social security number instead of my corporate EIN. Do I need to change that?

If you are an employee, you are an individual and your employer would need to use your Social Security Number, they cannot use a corporate EIN.  

A corporate EIN is only used for the corporation, not the individual. If you are saying a customer used your SSN instead of your EIN, what type of corporation do you have?  LLC, S-Corp, or C-Corp? Please provide more details if this is the situation. 

If you are self-employed, you don't have "employers", you have clients or customers.  If one of your clients issued a 1099-NEC with your personal SSN instead of your EIN, that is probably not a problem, since your EIN is linked to your SSN in the IRS records.  You would just report the income as normal business income for the business, not as personal income.