Can automations be set to change something in a Parent record when a Child record is modified?

I am trying to set up an Automation where when the MCD PO: field in the Child Purchasing Record is no longer blank, it changes the Vendor Checkbox field in the related Parent Record to Checked. I have it set the way I think it should work but when I try it, it doesn't work. Mind you I am new to Automations so I probably have something obvious set up wrong. Can someone tell me what that is?



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Chris Swirtz
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