Need help with thermals!

I bought 5 thermal polishes, my first ever moon cat purchase and I'm really excited to try them all! I've been having a bit of trouble with them. I used two coats of melonberry and jump jump bug (on different fingers ofc) and they were so beautiful and I was really impressed with how sensitive the polishes were to temperature and how quickly the colors changed. When I put on a top coat the colors changed to the "cold state" and haven't changed color much since, even in hot water the color only changes a few shades. Ami doing something wrong?