For example if we have $$ \ln{y}=a\ln{x}$$
If we raise both sides to the power of e:
$$ y = e^a .e^{\ln{x}} = e^ax$$
However by using log rules we get a different solution
i.e. by letting $$a\ln{x} = ln({x^{a}}) $$
then $$ y = x^a $$
Which of the two solutions is correct? Both seem to not violate anything but give different answers.
$$\ln{y}=a\ln{x} \implies y= e^{a\ln(x)}=x^a$$
You are confusing two rules
$$e^{a+b}=e^a.e^b$$ and $$e^{ab}=(e^a)^b=(e^b)^a$$