Automation not being triggered when an email is recieved

Inside of the Shortcuts app, I created an Automation. It runs a shortcut when I receive an email from my custom domain to an alias of my iCloud email. I've labelled "Sender" and "Recipient" accordingly. I've configured the "Subject Contains" to how I need it and set "Account" to "iCloud". Lastly, I enabled "Run Immediately".

Previously, I connected a Gmail account, and it worked when I used a Gmail as the recipient but not with an iCloud recipient.

I tried different variations and a restart, but it didn't work.

Is this a bug?