I’ve created some custom roles (with customer capabilities) which I then included in the list of the Shop manager editable roles (Admin Tools Module).
In the Users panel, the shop manager can change only to “customer” role, all the other roles won’t show in the dropdown.
I’ve also noticed that in the “Price based on User Role” Module (role&multipliers section), the shop manager can see only these roles: Shop manager, Guest and Customer.
Admin or a custom role (with admin capabilities) doesn’t have this problem.
It seems you did not upgrade your plugin for long. We did release two versions in the last two months. Actually, we have closed our previous upgrade process and changed that. So kindly please upload the plugin from the admin and it will work fine for the subsequent releases. We recommend all of our customers keep their plugins up to date every month.
Please check this and still if you are facing an issue you can provide us module configuration screenshots. We will check this from our side and help you.