It can take time. My bumblebee started close to 700g, my cinny started closer to 800g, my normal that I'm dinkering around with is around 600g and terrified, and my pastave is 300g and is starting to get the idea. And only the normal is eating.
Oh my goodness, they certainly vary! Good to know though, thanks for the input! I guess I'll give him a try and keep feeding him well (he eats med rats). Hopefully he will kick in soon!