Server.searchLdapUsers returns empty

We are using VRA 7.3 and writing some workflows. We are using 'User interaction' to halt the workflow till the user logs in the VRA portal and accepts.

In one of the environment, the function Server.searchLdapUsers(name, 0) returns valid values and the user is able to see the request in Manual Action.

But in another environment, the function is returning empty.

Question is, under what conditions/scenarios will the Server.searchLdapUsers function return empty. These are indeed valid values. The same name we get

values for function Server.findAllForType('AD:User', name); But we can't use the result as the 'User interaction' expects Array/LdapUser and we can't find a

way to convert the output of AD.User to LdapUser.

Any help is much appreciated. Thanks