Admin Login Leads To 404 Error

When logging in to our Admin area, the site wants to go to:

domain.com/admin.php?dispatch=admin.php

This gives us a 404 error. Should not the URL after login simply be:

domain.com/admin.php

Can anyone thinks of a reason why it is generating the ?dispatch=admin.php suffix?

Thank!

We never faced such issue. Please contact support team

Support ticket created #103203178

Thank you!