Comment 6 for bug 1922691

P.S. I have discovered a workaround / different approach which resolves this issue. Instead of using the "Browse annotations" option, if I instead open the book in the Calibre Viewer, and then open the right click → "Highlights" menu here which opens a panel on the right hand side, the highlights all appear in correct order, and can also be exported correctly with the Export button at bottom right.

Since I only need this feature occasionally, this workaround with opening one book at a time in the Calibre Viewer is perfectly adequate for my needs. :)