Because another page, linked to Create a Chat screen, is not sending data. You need to go to Chats - Employee page, and make sure that screen is also sending data to Create a Chat.
All inbound links to a page must send the same data for it to then be available.
But the two screens that are sending the data to this page are the same, the buttons on respective pages say they are sending the data but they aren’t.
And on the “Chats - Employee” page where the data is sending, this is the available data:
I haven’t seen your app but I have come across similar before if there’s a long chain of data flow. In this case I wrap the button in a list of organizations where organisation ID = current organization ID, for example. This refreshed the data flow for me in the past, and the list will pass on the data for you. Something to try perhaps.