New Syrian not warming up after 3 weeks!

[Inky]

I have a new little Syrian named Moon Pie, he was 2 months old when I got him 3 weeks ago. He does not try to bite but he is not warming up at all. He's in a Ikea Detolf cage with tons of bedding, toys and a great house. I've been following all the normal guidelines which worked great for me in the past. The big issue with Moon Pie is he is hardly ever out/visible in his cage. I go in his room (his cage is in spare bedroom so not a stressful environment at all) multiple times every night to try to interact with him. If he is out playing, he will usually go hide in his house or tunnel or something within a minute or two. The few times when he is out and exploring, I do not try to pick him up. I know that would stress him out. The only contact so far is about a week ago he let me pet him on the back for a few seconds while he was out but that proved to be an isolated incident.

I am just at a loss for how to move forward with taming when he won't even show himself.

Any suggestions are greatly appreciated!