Consider a frame of reference S' moving with a velocity $v$ along x-axis with respect to a frame of reference S.

Using Lorentz transformation, $x'=\gamma(x-vt)$, where $\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}$

$\implies \Delta x'=\gamma\Delta x\tag1$

Using Inverse Lorentz transformation, $x=\gamma(x'+vt')$

$\implies \Delta x=\gamma\Delta x'\tag2$

However, equations $(1)$ and $(2)$ are simultaneously true only if $\gamma=1$. This further leads to 2 different results for length contraction.

$$L'=\Delta x'=\gamma L$$
and
$$L=\Delta x=\gamma L'$$

Please tell what's wrong in this.