  Previously, we have shown in Li et al. (2018) that very weak $\gamma$-ray
excesses ($\sim 2\sigma$) appear in some Milky Way dwarf spheroidal galaxies
(dSphs, including candidates) and the combination analysis of 12 nearby dSphs
yields a local significance of $>4\sigma$. In this work, we adopt a longer data
set (i.e., the 12 years of Fermi-LAT data), the latest Fermi-LAT software as
well as background models to update the searches of $\gamma$-ray emission from
these sources. Very weak $\gamma$-ray excesses ($>$ 2 $\sigma$) are found in
the directions of three dSphs, including Reticulum II, Bootes II and Willman 1.
In the direction of Reticulum II, the peak TS value of the excess reaches
$\sim$11. However, different from the previous analysis with the 9 years of
Fermi-LAT data, now the location of the gamma-ray emission is significantly
away from the center of Reticulum II because of the enhancement of "offset"
$\gamma$-rays above 10 GeV since 2017. The detected weak excess is likely due
to the contamination of an astrophysical $\gamma$-ray source with a TS value of
$\sim 22$, irrelevant to the dark matter inside Reticulum II. The possible
excesses in the directions of Bootes II and Willman 1 are weaker with lower
peak TS values ($\sim 7$). If interpreted as annihilation of dark matter
particles into $\tau^+\tau^-$, the dark mass mass of $m_\chi \sim 14$ GeV and
$\sim 80$ GeV are found for Bootes II and Willman 1, respectively. Much more
data are needed to clarify whether these two potential signals are real and
then reveal their origins.
