Automate a change in a linked column

Hi

I have two boards - Board A is a Master List of Documents and Version Number and Board B is a tracker for staff who have to read the documents.

I have a link from Board A to Board B for the version number of the document.

Board B also has a Status Column for Read/Not Read

What I would like to do is have an automation that when the Version Number is changes in Board A - that the Status Column in Board B changes to Not Read. I have tried to create an automation on Board B to do this with the linked version number but it doesnt come up as a selectable column. I also put in a formula column in Board B to replicate what was in the linked version number from Board A but again its not selectable when I try to create the automation.

Any thoughts would be appreciated!