Cannot Sort Fonts

MainType 10.0 Professional

Cannot sort fonts. This used to work but now it doesn’t.

Sort by left-click on the column heading doesn’t work
Sort by View menu > Sort by doesn’t work

My Windows version is Windows 10 Pro 2004 Build 19041.630

Disable Toggle Family Grouping. When fonts are grouped by family, the fonts are sorted only within each family. Expand a family group tree to see the effects of sorting.