The New feature Clear All Slicers button (part of March 2023 release) works only for the 1st time in both desktop & Service. And it does nothing when you do some more slicer changes & try to use it 2...
I completly get it but i see some inconsistencies & mainly for single selects on version 2.116.622.0 64-bit (April 2023). Like it resets to 1st value in the slicer dropdown for 1st time but not from 2nd time onwards! But looks like it is resolved too in version 2.116.966.0 64-bit (April 2023). Thanks for checking & confirming the behaviour.