I just bookmarked this page on my toolbar on my Linux computer. see screenshot I'm going to go in my other room with my mac and see how long it takes for this bookmark to show.

It's here for me on my mac. see screenshot

Verify that you signed into sync on all devices.

I did all but to no avail. I use android phone, ipad, macbook. For example when I bookmark a page, it doesn't sync in myipad or android phone. When I do this in brave, it syncs within few seconds across platforms.

Sync settings? see screenshot

Yes, all are clicked in sync settings. When I remove for example 4 bookmarks in mac, it removes one or two in android phone or ipad. So not perfectly synced.

I agree as it is in chrome, brave, safari - unlike firefox. I use old macbook, firefox is the only one that gets updates, but unfortunately bookmark sync is a problem.