I found this article which also describes the issue at hand. It seems that applying rules to an email alias will not work on the same domain. I'm looking for suggestions to how else I might achieve my goals.
I'm developing a workflow to process packing slips. I've created an account scannerATcompany.com to use with our ScanSnap scanner. Scanned documents will be sent to this account's OneDrive which triggers a PowerAutomate workflow. For employees who don't have access to the scanner, we want them to email a photo of a packing slip. We have several offices which all have their own SharePoint sites where these packing slips need to be processed. So, for example, the NY office would email newyork.packingslipATcompany.com (an alias for scannerATcompany.com). The exchange rule would move any emails with attachments addressed to newyork.packingslipATcompany.com to the NYPackingSlip email folder. This would trigger a PowerAutomate workflow specific to that folder and begin the process of moving the file to the New York SharePoint site. Ultimately, I want to use one user account to trigger five different PowerAutomate workflows. I just don't really see how I can make this work without creating five different email accounts; which seems overkill and expensive for our needs.