Comparison of the 10 s fringe contrast, obtained across the KLMN bands, between before the group delay controller upgrade when fringe jumps were left uncorrected and after the upgrade when corrected in 82.5 ms. In the uncorrected case, the K-band fringe jump is simulated in the middle of the DIT, the worst case scenario. The K-band fringe jumps correction brings marginal benefits on the sides of the K band, but makes a very significant difference in the LMN bands of MATISSE.