Hello
I was setting up a Request portal for a new project, and while setting it up, I created a custom field with a field type of User Picker (single user)

I did test the request portal I created; users are appearing on my end. please refer to the image below, which shows users

But other colleagues cannot view the users, or there are no users found in the end. Please see the image below.

So far, I'm the only one that can view the users, and the rest of my teammates cannot. Is this related to user permission since I'm the admin?