With the other 2x magnified optics such as the ARCO and MRCO, the aiming reticle remains pointed correctly towards where the barrel is pointed (i.e. where the bullets will go).
However, this is not the case with the RCO and ERCO optics where as soon as you adjust your aim in any direction, the aiming reticle will significantly deviate from where the barrel is pointed.

If the ARCO and MRCO are configured correctly, then why are the RCO and ERCO not? The RCO and ERCO should be updated to work similar to the ARCO and MRCO.