This feature seems to be acting very buggy right now.
For some reason, linked record fields are not always updating properly for me, regardless of whether I specify the Record ID or the primary field name. It often results in failure, but not always. Very bizarre.
I was able to somehow get it to work again by re-testing my trigger multiple times. Then, it somehow kicked in and worked.
But this seems very buggy.
I think this shows that Automations is still in beta right now. Before Automations were introduced in Airtable, I created 95% of my client’s automations through Integromat (and 5% through Zapier), so I can definitely recommend those platforms as rock-solid platforms with almost no problems. Integromat is far superior to Zapier though, and has more features & functionality than Zapier does. (Note that I am an Airtable Consultant and a Registered Integromat Partner, and the Integromat link contains my personal referral code.)