CSV Marker Problems - Please Help

Hi all
Sorry if this has been raised but I can’t find anything on it.
I am evaluating Nuendo 10 after a break since N4. One of the winning features is the ability to import a CSV marker with dialogue, however I’m losing the will to live as every time I try no matter what tweaks I make I get
“Could not read timecode in the following rows:” and then all the rows listed, with the character, timecode in, time code out, and dialogue that I want to import. Choice is continue and ignore or continue and not ignore, the end result being the same - no import.
No hints on what is wrong, all the fields map during the import process and it shows the damn timecode in the error message rejecting the file. I’m following the manual to the letter, and have watched the tutorials on youtube.

Anyone have any suggestions?? Could anyone send me a template CSV which does work that I can then use going forwards? I have a ADR session booked Friday and would love to test run this as I’m desperate to be rid of ProTools - and this would clinch a lot of additional bookings for me.

It must be that the Timecode format is wrong.
Must be 00:00:00:00
Any other variant will not work. (Like 00.00.00.00 or 00:00:00)

HTH
Fredo