Bizare checksum error

I am trying to install leap 15.5 on an iMac27

First a couple of points:

The download checksum is correct
Install on other hardware eg nuc from the same USB stick works as expected
I can install other distros eg ubuntu eg arch on the iMac27

During install I get a dialog

CHECKSUM error hd:/ [abort][continue]

Continue seems to go no where. [lots of text menus, reboot, exit]

Does anyone know a work around or fix?
Thanks James

Post photo of this screen.

Will take a bit to organize this is the machine I’m using. Photo in (my) morning ie GMT 02:00 tomorrow

OK

Well, that’s rather different message than what you posted originally.

Could you switch to tty3 (Ctrl-Alt-F3) and post photo? linuxrc print logs on this terminal, it may give some more hints.

I did say bizare. I rebooted the same usb stick for 10th time to get the photo requested and a completely normal install happened. I accepted and did not try to break it.