Hello Kyle Owen, 

If you are referring to the Amelia Customer panel, the only way WordPress Users can access the panel is if they are connected to Amelia Customers. This connection is made in these cases: 

- the option Automatically create Amelia Customer userin Amelia -> Settings -> Roles settings is enabled, and then when someone books an appointment in Amelia they are created as customers in Amelia and as WP users with Amelia cusstomer user role

 - when Amelia customers are connected to a WP user on the Amelia -> Customers page, when you edit the customer they can be connected to a WP user only when that user has an Amelia Customer user role. If you need to have more roles for the ssame user in WP you can use some plugin for this purpose, like User role editor

- when someone  books an appointment in Amelia while logged in to WordPress, and the option Automatically create Amelia Customer userin Amelia -> Settings -> Roles settings is enabled

So, in these cases they can access both WP and panel while logged in to the WP and with the same  credentials. There isn't a possibility for Amleia to check the WP users' emails and connect them to customers, if that is what you want to achieve. 

If you have any further questions or concerns feel free to ask,

Hello Kyle Owen, 

Could you please tell me are these customers created with the 

Automatically create Amelia Customer user option enabled when they first booked an appointment in Amelia? Please check if these customers are connected to WP users on the Amelia -> Customers page when you open their modal.

When you say Amelia Customer logs in, does that mean a WordPress user with this user role is logged in to the back-end of WordPress or? 

Hello Kyle, 

You can check if these customers that mentioned they have issues are connected to WP users, when you go to Amelia -> Customers page and edit that exact customer.