Comment # 20 on bug 1177009 from Neil Rickert

It turns out that this might be a issue also with x86_64.

I have Tumbleweed 32-bit installed in an external drive.  And I have it setup
so that it can boot with legacy mbr booting, with 32-bit efi booting and with
64-bit efi booting.

Yesterday, I connected the external drive to a system with 64-bit efi booting,
but with secure-boot disabled.  And the Tumbleweed 32-bit system would not
boot.  It used to boot.  So I reverted grub2-x86_64-efi back to version
2.04-16.1 (the version just before the update around Sept 15th).  And after
going back to the old version, I can now boot it again with 64-bit efi.

By the way, to install x86_64-efi boot support, I use:

grub2-install --target=x86-64-efi --removable -no-nvram

For further testing, I have setup a VM with Leap 15.2 and Tumbleweed 32-bit
installed side by side.  In the Leap install, I used version 2.04-lp152.7.12.1
of grub2-x86_64.efi so that it can boot Tumbleweed.  Or I can directly use the
grub2 boot code installed from Tumbleweed (version 2.04-16.1) to boot either. 
Creating that VM was tricky, because of bug 1177849