Highlights and notes in Apple Books vanished

My Google search for an answer to my problem so far has found none. The experience I share with others is that notes and highlights, previously added to different books, have disappeared after reopening Books. And Apple Support for two years so far has been clueless re the cause or a solution to fix the problem.

I do not what to support Amazon but unfortunately, I will return to them for future book purchases because at least my notes and highlights and therefore a lot of invested effort are being saved. I find Apple's incompetence and non-existent service in this context rather disappointing!