There were no FATAL messages in the log if the credentials were changed. I can see now such line: [----] E, [2018-04-23T08:13:41.121296 #11900:8e7114] ERROR -- : MIQ(MiqQueue#deliver) Message id: [777], Error: [Invalid credentials for URL https://some_url/somne_manageiq_datastore.git]. I marked this as verified for 5.9.2.3.20180419182310_cab2891. Along with that, I've created another BZ https://bugzilla.redhat.com/show_bug.cgi?id=1570806, because UI flash message is missing.
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.
https://access.redhat.com/errata/RHSA-2018:1328