its the tren bro. dont sweat it. 25mcg a day of t3 while on aas wont cause muscle loss. When i did tren i lost alot of fat and only "gained" 3-4 lbs in 3-4 weeks. But i bet i really gained more like 10 lbs muscle, lost 7lbs fat.
make sure your protein is up, i know your carbs are if your using slin,
maybe your t3 is overdosed?