Profile: Support

>did you guys had override this service?

No, you changed it. I shared the native code from nopcommerce.
You can download the source code from official site and compare them.

Check it again.
You didn't do it.

This is a method from nop 3.90

        IPagedList<Customer> GetAllCustomers(DateTime? createdFromUtc = null,
            DateTime? createdToUtc = null, int affiliateId = 0, int vendorId = 0,
            int[] customerRoleIds = null, string email = null, string username = null,
            string firstName = null, string lastName = null,
            int dayOfBirth = 0, int monthOfBirth = 0,
            string company = null, string phone = null, string zipPostalCode = null,
            string ipAddress = null, bool loadOnlyWithShoppingCart = false, ShoppingCartType? sct = null,
            int pageIndex = 0, int pageSize = int.MaxValue);

You changed nopcommerce kernel libraries.
Check the class CustomerService, method GetAllCustomers.
Check the list of parameters.

Did you change the nopcommerce kernel libraries?

You can do using the native nopcommerce import

Ok, wait for the next issue.

Open the plugin configure page and enable debugging.

Try to reimport the ebay order and check the plugin log file.
P.S.
Open the order note for old eBay order and remove the first note with ebay order ID. the plugin will import the order again.

Check if nopcommerce task manager works (check your store URL).
This plugin is very popular, many customers use it.

1. Are we able to create new Product Specification Attribute Group via import?
No

2. Are we able to update/add options to Product Specification Attribute?
Specification Attribute and after it Specification Attribute Option
The plugin has several video on our YouTube
https://www.youtube.com/watch?v=YdjGpE3CHvE

1. Check if you configured the purchase event in GTM
2. Create the fake order and check if your order completed page has the tracking code