VTT closed captions are out of sync

Hi there,

have demo stream with VTT closed captions embedded: https://d1e9xzui4ifg72.cloudfront.net/m3u8/sun.m3u8

VTT is:

WEBVTT

00:11.000 --> 00:13.000
<v Roger Bingham>We are in New York City

00:13.000 --> 00:16.000
<v Roger Bingham>We’re actually at the Lucern Hotel, just down the street

Trying to play this stream with roku_stream_tester app, but for some reason first closed caption message appears right after video start and all other messages are out of sync as well.

Is there anything specific about VTT format I've missed or anyone had similar issues before?

Thanks!