Help fixing movies alias taking up 50Gb of space!

Hello,

My Macbook tells me that movies are taking up 50Gb of space:

But when I try to find them using OmnidiskSweeper, nothing is found.

When I search my Mac for movie files a lot of alias appear:

When I try to delete them and then remove them from library, nothing happens and they remain there:

This is the info available about them:

Can anyone help me?

Thanks,

Diana