Hi, ​@parsdabest!

That's normally something from Meta's side. I also have this issue with some clients from time to time. 

In some cases, you just need to wait some hours to “solve” the problem, in other cases, if I rebuild the flow, it works and in rare cases, I need to regenerate the URL or use some URL shortener to get it to work.

I'd suggest trying this out. 

Hope it works!