u/Equivalent_Raisin_23

Hey guys, i am first time dog owner and i got rough collie since he was puppy. He is now 10 months old.He has access to large backyard but now lately i have been having problems with his behavior.He sometimes wont eat the kibbles and COMPLETELY ignore my commands... he doesnt even respond to my presence but after like 3 days he goes back to being normal... and i am getting anxious...what should i do or what is he doing? Or he just eat too much sometimes?

I will be grateful for any advice, thank you.