Appending field values through automations not working

I’m running an automation that triggers on a record being created, it is meant to update a multiple select field “Users Created” by adding a new option value to the field. I used the general solution recommended by others which is:

The result being that it when it updates the field it returns an empty option value paired with new value, completely erasing any existing values on that field.

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I thought this might be an issue with the multiple select field but I tried it for a Long Text as well and it can’t seem to find the past values when I list it like this and gives this empty + new value result as well.

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So I’m not sure if I’m missing something small or if it is a bug. Any ideas on how to fix this would be appreciated, have spent a lot of time testing a bunch of things to get this to work with no luck.