Skoda Columbus maps not updating, screen shows "N/A"

Hi guys,

My first post. Not sure if this is the appropriate section to post this but here goes..

I have a 2015 Golf R with a retrofitted Skoda Columbus head unit,  similar or more or less the same thing as a VW Discover Pro MIB1.

As per the first image my setup is as follows:

The device part number is 5E0035020C
Hardware is H42
Software is 0389

(This first image was taken before my first successful update of the maps from version 39 to 68)

I previously successfully updated the maps from 2015 maps to 2018 maps Version 68 (ROW, as I'm in Australia) earlier this year.

The first time I updated the maps I had to use the SWDL menu as the unit, whilst recognising there was a new map version on the SD card, would not update with the standard menu in Navigation.

I downloaded the latest map, which is version 76 , from   https://webspecial.volkswagen.de/vwinfotainment/int/en/index/downloads/maps-download#/ , selected Golf R 2015 with the Discovery Pro unit, as before.

However, the head unit will not update the map through the SWDL menu. It recognises the new version 76 map on the SC card but it shows "N/A" on every screen, as per the second image . When updating the maps through the SWDL menu, I have to select several map components relevant to my location so everything updates. I get "N/A" on every screen

I've searched several forums, but can't find anything. I've also asked the same question on a VW forum but no one has responded, and thought I would come here given that my head unit is essential a Skoda item.

I suspect that the head unit firm ware may have something to do with it, as it is an early version.

I found a software version 411 for the Columbus and attempted to install it but the head unit said there was a conflict, so that didn't work.

Can anyone shed some light on this?