The general issue with multiple boot elements on s390x was indeed already identified back in 2017, and a ticket was opened and reverse mirrored to IBM (so it should never have worked that way):
LP 1736511 (and btw. RH ticket is referenced there as well)
The general issue with multiple boot elements on s390x was indeed already identified back in 2017, and a ticket was opened and reverse mirrored to IBM (so it should never have worked that way):
LP 1736511 (and btw. RH ticket is referenced there as well)