Hello! I am new here to this forum. I’ve had aquariums for many years now but am still learning. I recently switched aquariums from a 55 gallon to a 72 gallon bow front. I have 1 red tail shark(6inches), 6 tiger barbs(1 inch), 2 yo-yo loaches(2.5 inches) and 3 racer snails which I’ve had all prior to moving them to the 72 gallon. When they were all in the 55 gallon, the rts would constantly chase the tigers and yo-yos and was very dominant in the beginning, but then began to settle and wouldn’t chase them as often but was still acting normal and active. Now that they have all been moved to the 72 gallon, everyone seems to be very happy except my rts. It’s going on day 4 since being Put in their new tank and my red tail shark isn’t very active at all and stays at the top of the tank in the corner. The only time he is active is when occasionally one of my yo-yo’s goes after him (which was never an issue before, used to be the complete opposite) and so when he goes after him, he then darts rapidly all over the tank and then goes back to his same spot at the top. I’ve also noticed his dorsal fin has been staying extended as well. If anyone has any advice or recommendations, I’m completely open to whatever. As I stated, I’ve done much research, but am still learning. My rts has been with me the longest for about 2 years now and I really would like to find out and fix whatever issue is wrong with him, it almost seems as if he’s turned into a very peaceful fish and is now getting bullied by my others. I’ve also never heard of yo-yos being aggressive towards rts before, but only one of mine has seemingly become so, although it almost seems as play to the yo-yo, but not to my rts. Thank you all so much for taking the time to read and help!