Characters pronounce the name of the rare-earth element "dysprosium" as "DIE-sprosium". The accepted pronunciation is "DISS-prosium", just like dyslexia, dysfunctional, dystopia, etc.
Nia's 2021 phone would not be able to call Nia's mother in 2009.
The minivan that Alex drives has a license plate that says "Midvale" and the car that CJ drives has a license plate that says "Metropolis". No license plates in the US use city names. They should have state names (though the states where Midvale and Metropolis exist are never stated.)
When she talks to Alex at the college, mistaking her for Eliza, CJ calls her "Dr. Danvers", but there's nothing on Eliza's faculty badge that identifies her as such, and as an outsider from Metropolis, it's unlikely that CJ even knows that Eliza possesses a doctorate degree.
When CJ Grant talks to Alex and mistaking her as Eliza Danvers she calls her "Professor". Second is that before starting talk she looks at her badge on which is written Midvale College, Eliza Danvers, Professor, ID number: 12588985, Expiry Date: 12/04/2010.
When Brainy and Nia are looking at the future D.E.O. database, after Naxim Tork's status changes from captured to wanted, the words "Naltorian" and "Coluan" on the screen are misspelled as "Noltorian" and "Caluan", respectively.
The episode description states Midvale 1990 when actually it's 2009.
When Young Cat is looking at a map of Midvale, it is actually a map of Indianapolis, Indiana.