Search customer API doesn't return original email?

Shopify Plus
1

I am using customer search API on GraphQL to search for the first 10 users by email.

But I figured out that the original email of the user, who repeats deactivate & reactivate the account with the same email more than 10 times, are not returned by the API.

Expected behaviour

When I call customer search API and returns emails as follows.

xxx@example.com (original email)
prefix-of-deactivate-account_xxx@example.com (deactivated email)
xxx+11101@example.com (alias email)
prefix-of-deactivate-account_xxx+11101@example.com (deactivated email alias)

Actual behaviour

prefix-of-deactivate-account_xxx@example.com (deactivated email)
xxx+11101@example.com (alias email)
prefix-of-deactivate-account_xxx+11101@example.com (deactivated email alias)

API doesn’t return the original email anymore.

This happens only for the user who repeats activate & deactivate account more than 10 times.

I want to know it’s because of the limitation of shopify side or not.

Hopefully, I get hear from you soon, Thank you for your support!