State Taxes

You have to file a South Carolina nonresident tax return and pay South Carolina tax on the income that you earned for working there. Tennessee has no income tax, so you don't have to pay any tax to Tennessee and there is no problem of being taxed by two states. It doesn't matter where the 1099 came from.

South Carolina will tax the work performed in the state. Tennessee has no reciprocal agreement with any state for income taxes, because they have no income tax as @rjs notes. ‌You will file a non-resident return for the work performed in South Carolina. You don't have any filing obligation to Florida due to the address on the 1099 (also, Florida has no personal income tax.)

Here is a TurboTax article you may find helpful: How do I file a nonresident state return?