1. When you right click a (sub) category in the browser, you get a context menu with the single item “Open in Contact Sheet”. This is a pretty useless context menu since the selection is already shown in a search sheet… This happens with “reuse search tabs” enabled, with this setting disabled, the context menu is briefly shown but disappears immediately (the selection is shown in a tab as usual). See first screenshot
2. When you right click a (sub) clause in the filter, you don't get a context menu, but instead you get a very small bar. See second screenshot.