The document link within a notification email is a one-time link. If a signatory attempts to reuse it they will be redirected to send themselves a new link. You can extend the length of time the link will work to alleviate this effort for signers.
We recommend you use the one-use link and alter this setting only if required. The most likely scenarios that require a change to this setting are in connection with an API integration, or where a style of documents and/or demographic are more likely to incur revisits.
The number of hours the link is re-usable can be set in Admin > Signer Experience > Experience Options. Look for the label Signer access time before re-authentication (hours). Enter the number of hours you want the link to be valid for (from the time the link is first accessed). For example, enter 48 for 48 hours. Use 0 for one-time use only.