Conditional Logic Returning Invalid Input when Record Length = 0

Hmm I tried testing out an automation that had a conditional on a lookup of a linked field and it worked fine, and so I figure your setup's different.  If you could let me know what field you're looking up I'd love to test it out! 

Hello @Cole_Wedemeier 
First and most importantly, please show the field type of every linked record and some sample data. That makes more sense.
@TheTimeSavingCo you've tried one example, but the real issue here is the return type of data.

At first glance at your shared video, it looks like whenever data comes(with the right data), it returns an object and the length calculation is also different.
Just for a quick suggestion try "null" if it fixes your issue. Otherwise please share more table data types with some of the sample data.

👍

@dilipborad and @TheTimeSavingCo 

I have tried putting "null" into the conditional rule, but it just disappears and Airtable thinks the condition is not completely input yet.

I've created a sample base for you to see the fields and how they are interconnected. While that won't give you the automation, you can see the fields.

Let me walk you through that particular step in the automation. 
Conditional Goal: If someone does not have an Onboarding Form record, which is linked to the Client List table,  then send a gmail email to them. 

Records to work with: 
Client Rita = NO Onboarding Form
Client Crystal = HAS Onboarding Form

Conditions are in image. Note: the "Onboarding Form" is a linked record to the Client List. The Client List is then a linked record on the Results Tracking table to which the automation is being built on for a trigger of "When form is submitted"

Full Automation:
Trigger: When a form is submitted

Action: Update Record

Conditional Action 1: If total audience growth ≤ 0.24 AND Movement Makers Qualified (from client list) (from results tracking) length = 0

Conditional Action 2: If total audience growth ≥ 0.25 AND Movement Makers Qualified (from client list) (from results tracking) length = 0

Conditional Action 3 (where I'm getting stuck)
if Onboarding Form (from Client List) length = 0

@dilipborad I had to try several variations of the Find Record, but ultimately it was the solution. Thank you so much!