iOS 12 Sync with iOS 9.3.5

[Rhino1]

I was just wondering if anyone else is having troubles syncing their data across devices running iOS 9.3.5. All my iOS 12 devices are syncing fine and picking up changes made on other devices (iCloud Drive namely) however my iOS 9.3.5 SE is simply not syncing both up or down. Has compatibility been removed?

I've tried all the usuals;

sign in/out, reboot, hard reboot, enable disable, etc.
I havent created a new apple ID because all the other devices are working fine.
Truth be told all I want to do is sync Whatsapp chats in order to sync them to the iOS12 device and I don't want to use iTunes to bring it along.

Thanks.

 

[Rhino1]

Ok I finally have fixed the syncing issue but I just cant get WhatsApp to backup to icloud in the usual chats section. Its constantly stuck at 0% anyone ever had this issue?