  Based on the accurately calibrated interaction FSUGold, we show that
including isovector scalar $\delta$ meson and its coupling to isoscalar scalar
$\sigma$ meson in the relativistic mean field (RMF) model can soften the
symmetry energy $E_{\rm{sym}}(n)$ at intermediate densities while stiffen the
$E_{\rm{sym}}(n)$ at high densities. We find this new RMF model can be
simultaneously compatible with (1) the constraints on the equation of state of
symmetric nuclear matter at suprasaturation densities from flow data in
heavy-ion collisions, (2) the neutron skin thickness of $^{208}$Pb from the
PREX-II experiment, (3) the largest mass of neutron star (NS) reported so far
from PSR J0740+6620, (4) the limit of $\Lambda_{1.4}\leq580$ for the
dimensionless tidal deformability of the canonical 1.4$M_{\odot}$ NS from the
gravitational wave signal GW170817, (5) the mass-radius relation of PSR
J0030+0451 and PSR J0740+6620 measured by NICER, and thus remove the tension
between PREX-II and GW170817 observed in the conventional RMF model.
