John Gill Commentary 1 Chronicles 3:17

"And the sons of Jeconiah, the captive: Shealtiel his son," — 1 Chronicles 3:17 (ASV)

And the sons of Jeconiah
For though he was pronounced childless, (Jeremiah 22:30) , that does not mean he had no children in any sense, but none to succeed him in the kingdom:

Assir ;
which signifies bound, or a prisoner, because, as Kimchi thinks, he was born in a prison, his father then being a captive in Babylon; but rather it refers to Jeconiah himself, and is an appellation of him, and to be rendered,

the sons of Jeconiah the captive :
which agrees best with the Hebrew accents:

Salathiel his son ;
the same that is called Shealtiel, (Haggai 1:1) who was both the proper son of Jeconiah and succeeded him, as some think, in the honour and dignity the king of Babylon raised him to.