How to boot a 32-bit Ubuntu on a 64-bit EFI machine?

[Ulf Zibis]

Hi,

few years ago, I was able to boot my 32-bit Ubuntu on a 64-bit EFI machine with 
a 64 bit EFI GRUB. This worked fine for Ubuntu 16.04 and 18.04 over long time.

But since latest updates I get:
"Kernel does not support 64 bit cpu"

So my queston is, if there has something been changed in recent versions of 
GRUB which prevents from booting 32-bit Linux on 64-bit EFI machines.
Or is the cause to search for in Ubuntu's flavour of GRUB?

Regards,
-Ulf