I found this on the net after searching for "kernel 4.4 mdadm" (a page about mdadm - follow first link):
"Kernel versions in series 4.1 through 4.4.1 have a broken RAID implementation. Use a kernel with version at or above 4.4.2. "
I am using kernel 4.4.0-24 therefore I have broken raid.
I found this on the net after searching for "kernel 4.4 mdadm" (a page about mdadm - follow first link):
"Kernel versions in series 4.1 through 4.4.1 have a broken RAID implementation. Use a kernel with version at or above 4.4.2. "
I am using kernel 4.4.0-24 therefore I have broken raid.
Hope this helps someone else.