Thanks for reaching out, Tianchou.
It sounds like you're having trouble watching videos on your MacBook Pro. We can help.
First, we'd like to see if this is an issue with Google Chrome, or something else. The easiest way to test is to try watching the same video using Safari. Do you see the same behavior, different unexpected behavior, or does the video play normally?
If you notice the same behavior, or some other behavior while playing the video you wouldn't normally expect while watching in Safari, be sure to play another alternate video from a different source if possible so we can also rule out an issue with the content.
In the meantime, you can also check out the Google Chrome Help page: Fix videos and games that won't play for some steps that may help.
Keep us posted.
We are here for you.