What causes the gray box to appear in Facebook on iPad?

Rebarand wrote:

Many reports on people getting a gray box on their posts. Mainly iPad it seems. So what is the explanation?

Ask META facebook is their product, not Apples.

So what is the explanation?

If you are asking Apple, they will not see your question in this user-to-user forum. I have seen this same complaint for some time and with a variety of device makes and types. That says "Facebook" issue.

This non-Apple article suggests it is some kind of "Nanny" function built into Facebook:

https://techcult.com/why-is-my-facebook-post-grayed-out/

A web search for "gray box on facebook" turns up hits going back a couple of years. It is not Apple-specific and therefor Apple cannot fix.