  We explore the relationships between the [O/H] gas-phase metallicity radial
gradients and multiple galaxy properties for 238 star-forming galaxies at
0.6<z<2.6 selected from the CANDELS Ly$\alpha$ Emission at Reionization (CLEAR)
survey with stellar mass 8.5 < log $M_{*}/M_{\odot}$ < 10.5. The gradients
cover the range from -0.11 to 0.22 dex kpc$^{-1}$, with the median value close
to zero. We reconstruct the nonparametric star-formation histories (SFHs) of
the galaxies with spectral energy distribution modeling using Prospector with
more than 40 photometric bands from HST, Spitzer and ground-based facilities.
In general, we find weak or no correlations between the metallicity gradients
and most galaxy properties, including the mass-weighted age, recent star
formation rate, dust attenuation, and morphology as quantified by both
parametric and non-parametric diagnostics. We find a significant but moderate
correlation between the gradients and the 'evolutionary time', a temporal
metric that characterizes the evolutionary status of a galaxy, with flatter
gradients observed in more evolved galaxies. Also, there is evidence that
galaxies with multiple star-formation episodes in their SFHs tend to develop
more negative gas-phase metallicity gradients (higher [O/H] at the center). We
conclude that gas kinematics, e.g. radial inflows and outflows, is likely an
important process in setting the gas-phase metallicity gradients, in addition
to the evolution of the SFH radial profile. Since the gradients are largely
independent on the galaxies' physical properties, and only weakly dependent on
their SFH, it would appear that the timescale of the gas kinematics is
significantly shorter than the evolution of star formation.
