Climate control acting odd

Hi guys, I’ve got a 2013 Veloster + with climate control. It used to work really well now it’s acting strange, the a/c keeps turning off and on constantly and it keeps changing modes whilst in Auto. I’ve also just realised that it’s not heating well, on manual it’ll only blow hot air when set to highest temp 30° or max, set anything lower and it just blows cold ac air. I’m think the temp sensor is faulty? Anyone else had similar issue and managed to solve it? Cheers