Same as 7-mode as a whole the Unified Manager 5.x Core goes end of support by end of this year.
For ONTAP 9, please remember that Unified Manager 9.4 is also end of support for some time already.
I recommend to upgrade to a more recent release.
All Active IQ Unified Manager versions up the most recent 9.11 support all ONTAP 9.x versions.
The Unified Manager version should be higher/newer than your ONTAP version. Although UM supports ONTAP up to one release higher, you won't get the full feature set.
Kind regards, Niels