Please backport following patch. It enables systemd/cryptsetup to understand (and unlock) LUKS2 on disk format.
- b3b4ebab02395933cde554b5a5d5c363dae3920d (cryptsetup: support LUKS2 on-disk format)
qa_ack+ for RHEL 7.6
fix merged to staging branch -> https://github.com/lnykryn/systemd-rhel/pull/204 -> post
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.