Top: Uncorrected Fermi-GBM CSPEC data (1.024 s resolution) in the five NaI detectors with viewing angles to GRB 221009A below 60° at trigger time and the evolution of the MVT (﹩{\rm{\Delta }}{t}_{{\rm{\min }}}﹩) obtained from the Fermi-GBM non-BTI regions. The MVT ranges from ∼0.01 to ∼1 s. The decreasing MVT occurs in regions where the count rate is more variable. Bottom: Uncorrected Fermi-GBM CTIME data (0.064 s resolution) for the same two NaI detectors during the first Fermi-GBM BTI region.