Update 14-08-2023 PM
Just for reference - traced the problem down to the hard disk on the Giga Blue UE 4K
As mentioned - while looking at the logs in more detail I notice there was an I/O error when I tried to view the folder - ./pts_livebuffer_1 (via telnet)
To get around the error (and stop the infinite loop on boot up) I
1. Flashed the 6.2 image again but did not restore from my previously saved settings
2. During the setup wizard I again used telnet to access my device (via Powershell on my laptop)
3. From the telnet prompt I unmounted /dev/sda1
4. Ran e2fsck -p -f /dev/sda1 - accepting any recommendations to fix errors etc.
5. Rebooted the Giga Blue UE 4K
The HDD check and fix seemed to get it out of the infinite loop it was in; so I could at least startup successfully.
Once basics working I then flashed to the latest image 6.4.003 release.
All seems ok so far ! (fingers crossed)