OS X Yosemite shares browser tabs between two different Macs, although iCloud-Safari is turned off

Yesterday I got crazy with a very special behavior of two of our iMacs (running with the latest Yosemite).

If you open a browser Tab in Safari or Chrome on the first iMac, it automatically opens in the task bar of the second one (Screenshot).

I disabled the Safari Cloud-Tabs Service in the iCloud, but the sharing keeps on going (still after rebooting, activating and deactivating again).

Funnily enough, it doesn't matter which browser you are using. Opening a tab in Safari displays it with a "chrome remote" icon on the other computer.

Has one of you ever seen this feature? Both Macs are using the same iCloud-Address.

Btw: There is no Chrome "iCloud Tabs" Extension installed, but like I said this problem happens on Safari too.

If you really mean by automatically opens in task bar as a Browser icon displays a the little icon on top of it in the Dock (Handoff app icon in Dock ), and when you click it it opens the same page you are viewing on the other Mac.

then this is nothing to do with iCloud.

This a feature called Hand off. Have a read here

When your Mac computers and iOS devices are within Bluetooth range of each other (about 33 feet or 10 meters), they can automatically “hand off” what you’re doing from one device to another. For example, you can start writing an email in Mail on your iPhone, then instantly pick up where you left off in Mail on your Mac.

Handoff works with several apps that come with OS X Yosemite and iOS 8: Calendar, Contacts, Mail, Maps, Messages, Notes, Phone (iOS only), Reminders, and Safari. It also works with Keynote v6.5, Numbers v3.5, and Pages v5.5 for Mac, and Keynote, Numbers, and Pages v2.5 for iOS. Third-party apps may also work with Handoff.