I cannot delete keyboard shorcuts

The shortcuts are working, I can set new ones, no freeze BUT when I delete some, they keep coming back.
I tried to delete all of them, reboot my iPhone 6+, same result.

I also reset my keyboard dictionary, same problem.
It happens independently of any sync. with iTunes as I tried when I had deleted the shortcuts.
Same thing with iCloud.
They are deleted but come back.
Maximum time they had really disappeared was 12 h!!
As I have a few almost similar it becomes a mess very quickly when I type!

I've read a few things on other community forums. They have the same problem and no answer so far!

Very annoying and it's driving me nuts!