How does one enable/disable inline bot use in Telegram chats?
This issue seems to be due to a bug on the Telegram server's end. The bugged permission state can be fixed by disabling the "Send Stickers & GIFs" permission for chat members, and then re-enabling that same permission. A chat owner or a chat admin with the admin permission to edit chat permissions will need to perform this action.
The cause for this bugged chat permission is not yet known.