vendor not being able to register despite unique credentials

Describe the bug
as soon as you register the vendor an alert is prompted that already a vendor is registered with this email.

To Reproduce
Steps to reproduce the behavior:

Go to vendors
Click on add new
enter details
See error
Expected behavior
if there is an account on that mail it should be shown in the grid view

Screenshots
image

Desktop (please complete the following information):

OS: Windows
Browser Chrome
Version 122.0.6261.95 (Official Build) (64-bit)

No file or test is named. Reproduce the issue through Vendors > Add new in Chrome, then trace the vendor registration and duplicate-email handling. Done means a vendor with unique credentials can register, while an existing email is represented in the vendor grid as described.

Written by the indexing model from the issue text.