Thx - will try stuffing her - she gets hikari carnivore pellets which she devours and cut shrimp.Since no one has answered correctly I will chime in..
Your Stingray is hungry, that is why it’s spitting. I have some that will do this, half belly of food they’ll still spit until they are completely stuffed. Some Rays just like to be “fat”
Either increase the amount your feeding/frequency. If it won’t eat more then what you’re feeding then you likely have a different issue all together. Cheers!