The lookups on the ‘Account’ fields is not working in D365 portal in IE 11

In our project we are populating account lookup data based on logged in User on D365 Customer Portal. Account lookups are working as expected in google chrome and Firefox quantum and at same time not showing data in IE 10 & IE 11.

Our majority of business user using IE 10 & IE 11 and facing such issues on portal.

Any help would highly appropriated ...