Server Error while adding dependent (Edge)

Env: Preprod
Company: AP-TestCompany
Employee: Test Test
Steps

• Log in as Test Test (username ttest99901, password: Abrakadabra01*)
• (I had initiated a child birth QE first.)
• On Employee page, click on "Child 0"
• Click Add Dependent
• Enter: First name, last name, SSN, dob (3/1/2018), child relationship = natural child
• Submit
• Get error pop-up: "Server encountered an internal error. Please contact your administrator."
• However on Chrome - child was added
• And could add second child in EDGE too.

I may not have the customization right, however, the point is - user getting server error is a bug. Not sure if it can be reproduced. May be by adding another employee.