VLC 3.0.4 WebVTT broken CSS on some platforms

I am not sure what exactly is not supported, but (ignoring positioning and the rest of the cue settings, still to be supported under ticket #19377) the colors, shadow and font-size applied to cues 42, 43, 44 (at time 00:01:27.000) don't match what is expected.

I am attaching the .vtt file, how the font-size, color, shadows appear when rendering using libASS, and how they appear if we remove the styles altogether (native browser support, which doesn't handle embedded VTT styles and just reverts to CSS default).

I am using v 3.0.4, and the Font "Trebushet MS" is installed on my macOS Sierra (10.12.6).

We are testing VLC for playing WebVTT converted from ASS sources (by the packager, Kaltura's nginx-vod-module) and it doesn't seem to be any more usable than native browsers.

My guess is VLC is not handling voice spans, or not understanding styles correctly...