Lead Sources Overwritten

Lead Sources Overwritten

Hello,

At some point, I believe I may have overwritten the original values from within the Lead Source standard field. 

For example, let's say an original value for Lead Source was Partner and I overwrote that value to Web Form:
Now, when I receive leads from a webform via Zapier and specify the lead type = Web Form, the result I get for Lead Source when the lead posts into Zoho is Partner - not web form.

Unfortunately, I can find no way to repair this issue.

Any thoughts?