Centos 7 upgrade to AlmaLinux fail

On running through the following guide (and other similar guides) I get a green response on the Leapp pre-upgrade screen (then proceeding to Leapp upgrade) however when rebooting after the ELevate-Upgrade-Initramfs/Alma options fail to appear:

All I get are Centos7 option(s) of which will take me back into the command line as before.

It is worth noting that this is not a vanilla Centos server (as most wont be) however I have run the same process on a standard unconfigured Centos server with success already (just to confirm the process is correct).

Any ideas or pointers on where to check within Linux would be appreciated.