That sounds typical. This reminds me of my first pair, Lulu & Skadoosh. Skadoosh was more friendly, curious, and outgoing, while Lulu was so the opposite. It could be a long story to explain her personality but it sounds similar to yours only it took me weeks to realize she was frightened. Once I figured out it was her personality and her being afraid, I took a whole new perception of her. I began working with bonding, with both of them at the same time, using pouch time during the day and after some improvement began out of cage play.
I recommend not trying to split them up for bonding, do it jointly with both gliders. Also, if only one of you at a time can do it, then each of you spend time with both gliders.