(1) Notice at the top of the screen. If it has 'Ligo Translator' with a shield in front of it (shown in picture below). Ligo does not translate messages in this chat room.
You must invite Ligo to a group chat and set up language used in the group.
READ: "How to set up language"
(2) If you already set up language in the group chat, you must ensure that the messages you send is not in the language that you selected for 'Translate To'. Ligo does not translate the messages which are already in the language selected for 'Translate To'.
READ: "How to set up language Step 3.1"