Hey there. Have you filled out the how to ask for help form and posted pics of the entire enclosure yet? Typically they gape (hold their mouth open) when they are too hot and trying to regulate the heat or if they have a respiratory infection. Either of these should be addressed. Hard to know without the entire husbandry form filled out and full pics of set up. Here is a link to the how to ask for help https://www.chameleonforums.com/threads/how-to-ask-for-help.66/