Saved report filters on empty datetime values.

We are having an issue when users save reports that have date columns filtered to remove empty values. Whenever the user reloads the report the filter is ignored because Flexmonster believes the member is invalid: 

Error in predefined filter or members have not been loaded yet:

The filter can be reapplied manually through the UI and it utilizes the same filter string that was previously invalid with no issues. 

{
    filter: {
        exclude: [
            'next_future_or_past_task_due_date.[]'
        ]
    },
    uniqueName: 'next_future_or_past_task_due_date'
}

While testing this issue I created a simple button that when clicked triggered the following function: 

private addFilter() {
    this.$refs.pivot.flexmonster.getMembers('next_future_or_past_task_due_date', '', (members: any) => {
        console.log(members[0]);
    });
    this.$refs.pivot.flexmonster.setFilter('next_future_or_past_task_due_date', {
        exclude: [
            'next_future_or_past_task_due_date.[]'
        ]
    });
}

the console logs the first item in the member array which comes out as

{
"uniqueName": "next_future_or_past_task_due_date.[]",
"caption": "",
"dimensionName": "next_future_or_past_task_due_date",
"hierarchyName": "next_future_or_past_task_due_date",
"hierarchyCaption": "Next Future (or Past Due) Task Due Date",
"parentMember": "next_future_or_past_task_due_date.[(all member)]",
"isLeaf": true,
"children": []
}

and then immediately tries to use setFilter() to set a filter that excludes that member and we still get the:

Error in predefined filter or members have not been loaded yet:

Again, using the built in UI to set the filter works, it's only when saving the filter and then reloading the report, or trying to set it using the setFilter() method do we get that error. 

using a workaround like query filters doesn't solve the issue because the filters are not saved as queries when users filter using the UI, and users may decide to filter against multiple dates as well which means query will not work. 

Thanks for any assistance in this matter! 

Sincerely, 
Travis Bean