Twitter polls mean nothing, as they rely on convenience sampling and self-selection of respondents. Any time you use convenience sampling for polls, you only hear from the people with the strongest opinions, one way or the other. You don't get a representative sample of the underlying population.

Moreover, although Telemundo does lean left overall, they have also presented a racially biased coverage of the anti-racist protests. This coverage could bias subscribers against Harris, who is generally perceived as Black. This may have influenced their audiences' perceptions of Harris.

https://www.allsides.com/blog/univision-telemundo-accused-racial-bias