We have a game on Facebook instant games, a page for it and a server bot receiving gameplay events and sending messages to users (page_messaging). When a user first opens Fb page (buttons Play game, Message, Like on the right), clicks a Message button, he may write an arbitrary message (textbox in message window). But after the very first message from the server bot that textbox in messaging window disappears and a user can't write to a group any more - only receive messages. Has anyone faced this issue with UI on Web?
Tried on Web and Messenger app on iOS - no textbox. But Messenger on masOS allows to post messages even after receiving from bot.