We apply the automated AnomalyFinder algorithm of Paper I (Zang et al. 2021b) to 2018-2019 light curves from the $simeq 13,{rm deg}^2$ covered by the six KMTNet prime fields, with cadences $Gamma geq 2,{rm hr}^{-1}$. We find a total of 10 planets with mass ratios $q<2times 10^{-4}$, including five newly discovered planets, one planet that was reported in Paper I, and recovery of four previously discovered planets. One of the new planets, OGLE-2018-BLG-0977Lb, is in a planetary-caustic event, while the other four (OGLE-2018-BLG-0506Lb, OGLE-2018-BLG-0516Lb, OGLE-2019-BLG-1492Lb, and KMT-2019-BLG-0253) are revealed by a ``dip in the light curve as the source crosses the host-planet axis on the opposite side of the planet. These subtle signals were missed in previous by-eye searches. The planet-host separations (scaled to the Einstein radius), $s$, and planet-host mass ratios, $q$, are, respectively, $(s,qtimes 10^5) = (0.88, 4.1)$, $(0.96pm 0.10, 8.3)$, $(0.94pm 0.07, 13)$, $(0.97pm 0.07, 18)$, and $(0.97pm0.04,4.1)$, where the ``$pm$ indicates a discrete degeneracy. The ten planets are spread out over the range $-5<log q < -3.7$. Together with the two planets previously reported with $qsim 10^{-5}$ from the 2018-2019 non-prime KMT fields, this result suggests that planets toward the bottom of this mass-ratio range may be more common than previously believed.
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