The attribute “event_end_after” isn’t respected.

I have the short code:
[event_board event_category=”MyEvent” event_start_before=”first day of august + 1year” event_end_after=”first day of august” showpastevents=true]
I expect all events from last 1st August through to 1st August next.
What I get is all events from today.
I tried “First day of August” in https://docs.wp-event-organiser.com/querying-events/relative-date-formats/ and it is the correct format.

Any ideas?

Thanks – Will