At April 8, 2019, the specification of Google Apps Script Project was changed. You can see this at Google Cloud Platform Projects. The official document says as follows.
Warning: Starting on or after April 8, 2019, the Google Cloud Platform Console won't be able to access the default GCP projects created for new Apps Script projects. Older, existing scripts may have default GCP projects that are still accessible, however. If you have a new script and require access to its GCP project from the Google Cloud Platform Console, you must use a standard GCP project.
And then,