@leocg that's fix it for me but the fact that opera is a really slow browser compared to Firefox that even with all the extension installed remains very fast. That's a fact and the team should fix this issue.
until now 3/12/23 I'm not having anymore sync problem so this is a good thing
In 'other speed dials', go to the folder with the name of the device you want to copy from and select the items you would like to copy by clicking on the 'check' icon. Then right click and select 'copy' or use Ctrl + C.
Go to the 'speed dial' folder in the same place, right click and select 'paste'. Or use Ctrl + V.