In the "Customize message aggregation modes" dialog, "Groups and Threading" tab, the following select boxes show a neutral state ("-"): - Group expand policy - Thread leader - Thread expand policy When cloning a preset aggregation mode, the items get enabled. However, the three select boxes still show "-" and don't provide any options. Only after changing "Grouping" resp. "Threading", the sub-options appear. Now the values also appear for the preset modes. Reproducible: Always
Fixed in 4.9.4