I’m using MacOS Safari 14.0.1 on Catalina 10.15.7 on an iMac and a MacBook Pro, and iOS 14.2 on my iPhone and iPad. On MacOS Safari, I can open a new tab with the default start page, and one of the start page options (see lower right of the page) is to include iCloud Tabs. Those work great, and I can choose which device to get my tabs from (there are up and down arrows to the right of the device name). So give that a try.