@darkeagle9072 Type Info board (you can see it in the first image) says that synchronization is running fine and that 443 bookmarks were synced.

Same here, I tried pressing import sync but it doesnt said it syncronizing or anything

@burnout426 man, I made a point of logging into opera just to thank you for the explanation. it was the only good explanation I found on the internet to solve this problem, and it worked. I've been using opera for years and it has always been the best browser for me, but recently it has been heavy on my computer, even though I have already formatted it. I'm testing the edge. anyway, you were awesome, thank you very much.

The problem is most likely the file size. I have some 800 bookmarks but no favicons, so the file size for the .html file is less than 200 kb. There is a way to remove favicons from a bookmarks.html file. See this page and look at step 2.
https://www.ghacks.net/2009/05/11/how-to-remove-favicons-in-firefox-bookmarks/

@leocg Thank you.