Hi,
We (Zoho Assist) are planned to integrate our product with Jira Cloud Platform. We chose OAuth 2 authentication model for using Jira Rest Api's. We are facing some issues in getting Jira Issue Details.
Getting Refresh Token and stored in our instance is successfully completed.
OAuth 2 Scopes:
write:jira-work read:jira-work read:jira-user offline_access
We are able to get access_token from stored refresh token using Token Url.
We can get available resource (cloud_id, name , scopes , avatarUrl) using access token by below api
https://api.atlassian.com/oauth/token/accessible-resources

But we are facing issues while getting Jira Issue Details with same access token by below api.
https://api.atlassian.com/ex/jira/{cloudId}/rest/api/3/issue/{issueKey}

Always it returns 403.
It works while we tried to get Jira Issue Details using Basic Authentication. So we are expecting that there may be issue in OAuth2 model or we may miss something. Help us to sort out this problem.
Note: It was working for long time. We are facing issues from last Thursday (Oct 12).
Check and let we know if we miss anything related to Oauth2.