Extract text before first comma in lookup field

[Solid_Build]

Hello Airtable world,
We’re trying to extract customer’s names from a lookup field of a synced table where the names sometimes include a second name after the comma. Our data usually looks like this:

John Smith
Jane Doe, Terry Doe
James Bond

We’d like to be able to have a column that displays the following:

John Smith
Jane Doe
James Bond

So far we’ve tried the functions below, both returning and error.
IF({Customer's Name}, REGEX_EXTRACT({Customer's Name}, "[^,]*"))
LEFT({Customer's Name}, FIND(",", {Customer's Name}) -1)

The number of characters is unpredictable both, before and after the comma. I suspect the biggest issue is that our primary field from which we’re hoping to pull information is a lookup field and not just simple text. Is there a solution to achieving this?

[Kamille_Parks · Accepted solution]

Lookups usually return as arrays, and the functions you’re using only work on strings. Solve this by replacing {Customer's Name} with {Customer's Name}&"", which converts the array into a string.

[Solid_Build]

Solid_Build:

IF({Customer’s Name}, REGEX_EXTRACT({Customer’s Name}, “[^,]*”))

Amazing, thank you so much!