The VideoLAN Forums

Hello,
As the title says, vlc lags with 4k and subtitles. Without subtitles file streams without any issues
I am investigating it on my own end as to what may be the cause.

If anyone has any ideas do tell

It's a known problem, It's because the chipset on your TV can't handle properly the process of embedding the subtitles into the images (i.e. transcoding in realtime).
Try closing background running apps, it's a bit better for me.