I tried having each put in the slot and when I have them independently put in the slot they are working.
My only concern is since these are of two different speeds will that effect in anyway. If not then I will try to connect both of them at the same time.
if they are working together there's will be no negative effect but as you've told they are not running together ( the most probable reason latency/timing mismatch ) you can do not much here.