Utau Help- Ust sounds funny no matter what I do


Teto's Territory
Okay so I'm trying to cover Magnet. I'm using an ust from someone and before it sounded just fine. Then I tried to do Lukas part with Tei. She sounded fine but I wanted to see if a different utau would sound better with Mikus part so I did that, this is where my problem starts. No matter what utau I use (Elu Amaga, Gahata Meiji, Sukone Tei) it sounds really off? There's this weird distorted effect and pop effects. I thought it could be the flags I used (C25g-3BY6E99P30) so I tried a different one (g-3C100E100G). Didn't work. Cleared the flags completely and reset things. Still didn't work. Then I went back to Mikus part and the problem continued over there despite it being fine before. I'm not sure what to do? I've used that flag before on a different ust and everything was fine. But now everything's all robotic, distorted and popping. Any suggestions? I've just started utau again this month so I'm fairly new to everything.

The Utaus I was going to use were; Miku's part- Anna Nyui Colorful, Luka- Sukone Tei