[cypher]

It doesn't sound as though you're doing anything wrong to me, all hams take different amounts of time to tame & I do see plenty of other posts from people struggling with taming, if you think about it people are much more likely to post photos of their hams if they are tame so you don't get to see the whole story!
Just take your time & go at his pace, even when they do take a step back & lose confidence it's very rare for it to be lasting.
I forgot to say before when you do get him out again & put him in a play area or bath put some familiar things in there, toys & maybe even the wheel from his cage, if you can grab a handful of substrate & scatter that around too & he should be a lot more comfortable with his time out.