It's expected that the blur will only be present when using the main, zoomed in optic, but not when using the backup sight.
If it's not possible to separate the blur settings between the two optic modes, I suggest removing the blur from the main optic as well so it's like the ARCO and RCO as the blur is barely noticeable in the zoomed in optics but it's really making the backup optics inferior to the other red dot sights for no good reason.