Inconsistency of the built in 'contains' function on records fetching

Inconsistency of the built in 'contains' function on records fetching

I have a form which has a lookup multiselect field having as reference the ID field of another form. This multiselect lookup  field is then longlist type. But when I try to fetch a record, something like this

  1. SelectedUser = Users [AssignedActivitiesIDS.contains(45465465468465464)];   // AssignedActivitiesIDS is a lookup multiselect field

the following error appears

The operator :'contains' can be applied only to String or List expression.But an expression of type :'BIGINT' was found

In other contexts, contains function works OK  - for example the code below works without an error

  1. if (AssignedActivitiesIDS.contains(45465465468465464))
    {

    }


It seems that the problem is only on records fetching. In this case, to get the needed results, I need to create a formula field (AssignedActivitiesIDS.tostring() ) in order to convert the longlist to string  - it's a workaround.

I hope that this problem will be fixed.

Regards,
George