Bad request on search on non-accessible project key

Authentication completed using Oauth Code Grant Flow. Can retrieve the list of projects.

Using a search on all project keys such as:

https://api.atlassian.com/ex/jira/GUID/rest/api/3/search

raises on a project key like:

project = ‘BLABLA’

an error: HTTP 400 Bad Request, with payload:

{"errorMessages":["The value 'BLABLA' does not exist for the field 'project'."]
,"warningMessages":[]
}

This seems to signal that the user has no access (Forbidden).

However, the key ‘BLABLA’ is returned as a value from the Projects API.

Is there any way to determine what projects returned are actually accessible by the JIRA user?

The HTTP 400 Bad Request problem of course does not occur when the JIRA user has access to all projects.