Do you know what day that was used? One week should be Sunday to Saturday. If you can replicate and have screenshots, please share, but may need a support case.
We’ve got a feature request raised for this - this was something possible in the legacy SIEM dashboarding (looker embedded) without needing to filter this within the search logic.
There is a way around this (and you can get quite nifty with it to solve a lot of other time filtering requirements). The below example should do the job though for this requirement!