How to disable Chrome/Safari notifications on multiple devices
This sounds like Handoff. Handoff lets you continue an action you start on one device on a different one (e.g. browsing a webpage).
If not already, you have to disable it on every device.
On OS X:
- Go to System Preferences > General
- Deselect Allow Handoff between this Mac and your iCloud devices
On iOS:
- Go to Settings > General > Handoff & Suggested Apps
- Turn off Handoff.