6.6 Beta - Synchronise > Transfer Settings > Exclude Directories makes sound and is ignored

using 6.6 Beta (build 17087) Windows 11
If I select Synchronise, Transfer Settings, Exclude Directories I get a "bong" noise and nothing happens. Actually any menu selection off "Transfer Settings" does this as does selecting off the "OK" button menu in the synchronise popup.
The subsequent Synchronise operates on everything.