I worked in another state in 2019 for 6 months but never changed my residency. Do I have to claim that lived in that state?

If you did live there for 6 months then you should answer "yes".  Each state has different rules.  If you would provide more information on your situation and what states are involved, we can provide a more complete answer.

If you have now moved to another state, that would now be your resident state unless you intend to return to your" home state"  If this is the case you would need to file 2 part-year state returns.

If you are still living in your "home state" , then you would probably need to file a resident return for your  "home state" and a nonresident return for the state where you worked for 6 months.

You need to prepare your nonresident state return first so the software can calculate the amount of credit on your "home state" for the tax you pay on your nonresident return.