Since updating to version 8, abstracts I have manually entered during the current session have disappeared when I synced with my Zotero web account, requiring re-entry. Past manual abstract entries seem to still be in place. I had to re-enter multiple times the first time this happened and saved the abstract as a separate Word document. Just now, I updated to Zotero 8.0.3 and found the manually entered abstract has disappeared. I re-entered it once and now Zotero 8.0.3 seems to keep the abstract.
I am on a MacBook Pro with up-to-date OS, up-to-date Safari and up-to-date Zotero.