What is the difference between the green line and the red line on the record?

[CTS_admin]

Hello.

Please tell me about the green and red lines that appear when I open a record.
I have an automation using webhook to get the information into Airtable when an appointment is made from the booking calendar.

The text information of the booking details goes into one cell which is comma separated. (Automation up to this point)

I then add a comma-separated formula to put the information into the other cells.

However, even though I have not changed the formulas, I am getting an error that the commas are mysteriously delimited.

When I check the difference, there is now a hyphen with a red line where there was not before, as shown in the screenshot.

I don’t know why this is there.
I would appreciate it if you could tell me.

[ScottWorld]

The red line means that there was an empty space that was previously typed into your long text field. The empty space was then deleted to make way for your new data that you pasted into the field.