I’m having the same problem for the past few months with lists. For example, I keep a list of books I read. It’s a numbered list, and when I finish a new book, I added it to the list: title, author. Sometimes the same, one appears twice in the list; sometimes three lines in a row are duplicated. And sometimes, part of a list entry is cut off, such as half of an author’s name.
I use Obsidian Sync, and my subscription runs out next week, and I’m thinking of switching back to iCloud. I started using obsidian Sync a year ago because of all the problems that were with iCloud, but now that iCloud has an option to keep all files, downloaded, iCloud syncing should work correctly.