Tempo track warps video?

So I’ve got a video and set some piano to it. I created a tempo track, as one does.

Trouble is: when I change the tempo, the video’s length goes along with it. If the tempo becomes slower, so does the video. If the tempo gets faster, so does the video. Not ideal.

There must be some basic setting I’m missing like the musical/linear mode for instruments, but as far as I know the video track doesn’t have that option.

Here’s a gif of it in motion.

Any ideas?

no that’s not true…
the Beats and Bars display doesn’t represent a fixed time
the time it represents highly depends on the tempo
so changing the tempo will change the time in the view

Same happens to audio tracks that are set to linear mode not to musical mode…