@K.Seastream Thanks for reaching out to Microsoft Q&A, apologize for any inconvenience caused on this.
As mentioned in the documentation, under limitation and considerations sections as shown below.
Currently creating a share point indexer using the delegated permissions mechanism is broken. Alternative method, to create a share point indexer is using application permissions.
I hope the answer helps. Please let me know if you have any further queries.
Please accept as Yes if the answer provided is useful, so that you can help others in the community looking for remediation for similar issues.