This question is for the Jehovah's Witnesses? They teach Jesus Christ is "a god," so how is it that all the fullness of deity dwells in Him?

The NWT explicitly states in John 1:1 that Jesus Christ is "a god," yet Colossians 2:9 states, "For (or because) in Him all the fulness of Deity/Godhead dwells in bodily form." This is backed up by Colossians 1:19, "For it was the Father's good pleasure for all the fulness to dwell in Him." "Godhead" is defined in Strongs Lexicon: https://www.blueletterbible.org/lexicon/g2320/kjv/tr/0-1/ In Greek, the word is "theotes" and Strongs #G2320. So how do Jehovah's Witnesses reconcile their claim that Jesus Christ is "a god" with the Greek meaning that Jesus Christ is actually God in nature or essence?