When I'm out riding on my Cobx,?

Changing to a "different bit" is usually the first resort for people having problems, but it usually NOT the answer! Firstly, have you had his teeth checked? Has he got wolf teeth for example, which could be interfering with the bit? If not, it is probably just that he is not accepting the bit. I would probably continue to ride him in a bitless bridle if this works well with him. If you want to get him accepting the bit: When you say you ride with soft hands, which is good, are you sure you are not riding with sloppy hands? Sorry, I don't mean to be rude at all! You still need to maintain a contact with the horses mouth. Make sure you have your reins the right length and are maintaining a contact and try moving the bit quickly but gently in his mouth until he comes down on the bit and then maintain that contact. Good luck!