Hi @Tharding - what is happening is Marketing Pro's audience tool is trying to automatically detect the first & last name for the merge tags used in the campaign builder. For your first example, it's trying to detect the first name by taking the first text string and last name by taking the last text string. For example, if the name was John & Mary Jones then it would pull "John" as first name and "Jones" as last name. In your second example, the algorithm is trying to rectify a common issue where names are entered as LastName, First Name. So, when it detects a comma in the name it automatically swaps the FirstName and LastName designators.
This is all really good feedback for ServiceTitan, because this could be resolved if they had an option for First Name and Last Name fields on the Customer & Location records themselves. I had submitted an idea for this a while back, I encourage you to upvote it: Separate First Name Field and Last Name Field in Customer and Location Profiles
In the meantime, I suggest using Reports instead of Audience Builder to grab the names in the original format as shown on the Customer record.
