The multiplicativity conjecture for reduced Weierstrass isomorphism classes

Let $n=p_1^{e_1}p_2^{e_2}\ldots p_l^{e_l}$ be an odd composite integer with $e_i\geq 1$, and let $C_R(\mathbb{Z}_n)$ denote the number of isomorphism classes of reduced Weierstrass elliptic curves over $\mathbb{Z}_n$. Reduced Weierstrass multiplicativity conjecture. The expression for $C_R(\mathbb{Z}_n)$ is multiplicative:

$$C_R(\mathbb{Z}_n)=\prod_{i=1}^{l}C_R(\mathbb{Z}_{p_i^{e_i}}).$$

The conjecture is obtained from computational data, and the source states that the remaining cases are open problems.