Contextual menu frequently disappears in Libraries panel

In Adobe Illustrator (29.8.1) on Mac OS 26.0, I frequently need to duplicate library items: all of my vector icons share a canvas size and other attributes, so when new icons are ready for adding to CC Libraries, it's easier to just dupe existing items and rename the dupe, before pasting in my new icon (side complaint: Illustrator still defaults new library assets added from an Illustrator file  to "align to pixel grid," which requires extra work on my part to mitigate). Recently, the contextual menu in the Libraries panel (invoked by right-clicking on a library item) is just not there. Restarting Illustrator doesn't fix this issue (although restarting my Mac does).