new rider not being able to be added

Describe the bug
upon adding the website generated an alert saying that there was another rider with the following credentials, where as when i looked in the grid view there was no rider with the same name.

To Reproduce
Steps to reproduce the behavior:

Go to 'riders'
Click on 'add new'
fill details and save
See error
Expected behavior
the rider should have been registered.

Screenshots
image

Desktop (please complete the following information):

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

Start in the riders area and reproduce the failure through the Add New flow using the reported Chrome environment. Inspect the save request and duplicate-credential validation to determine why a rider absent from the grid is rejected. Done means a valid new rider can be registered without an incorrect duplicate alert.

Written by the indexing model from the issue text.