Let $(d_1,Q_1)$ and $(d_2,Q_2)$ be ECC key pairs over two different elliptic curves (say NIST P-224 and NIST P-256). According to the Elliptic Curve Discrete Logarithm Problem (ECDLP), if the private keys were generated randomly, it is infeasible to find $d_1$ from $Q_1$ (or $d_2$ from $Q_2$).
Now, say we know $d_1=d_2$. That is, we do not know the private key (it was generated randomly) but we do know it is the same for both public keys.
Does this situation compromises the security of the ECC key pairs?
Is it now possible (or even easier than before) to find the (shared) private key?