Refreshing access_token is not following any certain timeframe

[Supermetrics]

We're having an issue with Adobe Analytics 2.0. Some of our customer's access_token is getting refreshed everyday that means they've to authorize to Adobe Analytics daily. But we've cases where many customers are using the same token successfully which has not been refreshed in a week or so. 

We would like to know if there's an issue with the refreshing token behaves differently. 
Thanks

[mesood · Accepted solution]

The default expiry of access tokens is 24 hours. You can refresh an access token without prompting the user for permission again even if a user is not present. The refresh token, by default, expires in 2 weeks.

https://www.adobe.io/authentication/auth-methods.html#!AdobeDocs/adobeio-auth/master/OAuth/OAuth.md