Are there lost tribes?

I do not believe so,

¹⁶ Those from all the tribes of Israel who set their hearts on seeking the LORD God of Israel followed them to Jerusalem, to sacrifice to the LORD God of their fathers. (2 Chronicles 11:16

And,

¹James, a bond-servant of God and of the Lord Jesus Christ,

To the twelve tribes who are dispersed abroad: Greetings. (James 1:1)

Two witnesses that the twelve tribes survived.

References

2 Chronicles 11:16

James 1:1