Does the existence of a sin, such as perjury, prevent the acceptance of an atonement for a vow or an atonement for delaying a vow?

Whoever is liable for an expiation due to a vow, an oath, or otherwise, must fulfill it immediately according to many jurists. Their expiation is accepted, and their obligation is discharged upon performing it, even if they have committed minor or major sins, and they are not required to repeat it. However, the sinner must repent from their sin, for sins may nullify good deeds and remove their rewards.