Discover Pro clock GPS v's time zone woes

[The J Man]

I'm tearing my hair out trying to sort this out
Daylight savings ended on the weekend so I figured, time to uncheck the DST box on the ol' satnav

Turns out that over summer time zone was set to GST+10 and DST was NOT checked
In Sydney, this is clearly wrong.

I now have to set time zone to GST+9 to get the correct time

The DST box is NOT selectable

Looking for any clues from the clue store

I have a MY17 TIG 162 (2016 build) with the Discover Pro (Gen 1)

Edit: well it LOOKS like a Gen1, but the manual says it's Gen2 ... WTaF?

[The J Man]

Aww man I think I've been through this before!

Was able to set time/dst properly when car was not running (i.e. in the equivalent of the old school 'accessories' mode)