I just checked your files.
Look at the timestamps :
1
01:00:00,000 --> 01:00:04,208<b>Cibicom’s new flexible slimline® towers</b>
<b>are fast to deploy.</b>
2
01:00:04,750 --> 01:00:09,666<b>The carbon footprint is reduced with up to 40 %</b>
<b>compared to standard solutions. </b>
They start at 01:xx:xx,xxx - The video clip is one minute.
It should be :
00:00:00,000 --> 00:00:04,208, etc.
Your timeline starts at 01:00:00:00 (I personally changed it in the settings) I guess it's why when you exported the the subtitles, they started at 01.
Just do a quick search and replace 01:00 by 00:00 in a text editor, it should work (I tested in with VLC).
I don't know why it's 01 by default. I always found odd to see the timeline starting at "one hour".