How to search issues in bulk from a list of issue keys

[Ade]

When using the user interface to make an advanced search for issues, the jira frontend makes a request to the following endpoint and displays the results just fine:

https://myinstance.atlassian.net/issues/?jql=key%20in%20(ABC-123%2CXYZ-456)

But when running the comparable jql query using the rest API (using the same user for authentication, with proper project access):

https://myinstance.atlassian.net/rest/api/3/search?jql=key%20in%20(ABC-123%2CXYZ-456)

The results are empty:

{ "startAt": 0, "maxResults": 50, "total": 0, "issues": []}

any idea why the above isn't working?

edit: the REST API is access with a user token and not the password. Using another user credentials, the REST api call works fine, seems it's not a jql issue...