How did you conclude that the original poster has version 38.4?
Also, what makes you think that versions which are applied to 2020 hardware would be in the same sequence as software for 2018 hardware?
Also, what makes you think that versions which are applied to 2020 hardware would be in the same sequence as software for 2018 hardware?
There's an update that updates the Uconnect to 40.1 from 38.4 which looks like the version you have.