Hello, As instructed I've cloned the original defect for my customer's issue with this not being completely fixed in OCP 4.6.17. From what I can tell, we are no longer seeing the "Failed to start transient scope unit: Argument list too long" being logged, but we still get lots of "Failed to set up mount unit: Invalid argument" with the mounts failing. A new sosreport from 4.6.17 is attached to the case and can be accessed via supportshell. Thanks!
moving back to node until there's evidence this is someone else
upon inspection, this is looking suspiciously like https://bugzilla.redhat.com/show_bug.cgi?id=1884800, sending over to storage for futher triage
If you see only "Failed to set up mount unit: Invalid argument", it's really duplicate of bug #1884800. There is not an easy way how to fix it, however, the message is completely harmless. No data is lost, everything is mounted as it should be. *** This bug has been marked as a duplicate of bug 1884800 ***