When opening the Bookmarks window, the contents of the table on that screen is misaligned: the top-most item is "shown" above the top edge of the table's viewport. Hence, it's impossible to reach those items.
The workaround is to click an edge of the window. I assume this forces a redraw that then properly aligns the table's contents.
See video for "evidence."
Any table content is aligned properly AT ALL TIMES! 😉
Orion 1.0.5 / macOS 26.4
Tahoe (26)