Export email doesn't use filter

Export email doesn't use filter

I've created a Tabular view report which I need to send to different email addresses based on the Project "Group ID".  Regular export keeps whatever filter is current but export to xls scheduled email doesn't always keep the filter.  Usually, it doesn't but I've run the same scheduled export email more than once by just changing the send time and have gotten an export that has the filter and others that don't use a filter.
I've created separate reports so I only have one filter in place on each report and this still doesn't help.

What do I need to do to have a scheduled email export to .xls keep a particular filter?