The Fifth Circuit has determined that the 30 day filing deadline in 8 U.S.C. § 1503(a) is a claims processing rule. The court further determined that “a denial of a timely motion to reconsider or motion to reopen may serve as the final administrative denial on a particular claim. If the motion is untimely, then the AAO decision is final.”
The full text of Villegas Sarabia v. Noem can be found here:
https://www.ca5.uscourts.gov/opinions/pub/24/24-50750-CV0.pdf