It’s like an invisible block, with 0 warnings from Facebook but i know it’s there.
Do you share your videos on other pages/groups?
Do you use black stripes on the video?
What do you mean by "invisible block"? If it's invisible, how do you know it's happening? I mean, what makes you think you have that block: the reach went down, you can't post some kind of posts, etc.
I share my videos but nothing like spam. Very very veryyy few shares. I'm very cautious about that. And I never use black stripes.