Sometimes if you leave the room or watch in the distance they think your gone and get in.
Or you can be persistent and egging them on to get in but if your worried your over stressing them by constantly badgering them to get in then a good way to pick up a bunny (or most animals smaller than a dog) is to get a towel or a blanket and lightly drop this over them, it will confuse them for a minute so they stay still long enough for you to scoop them up. Scoop him up and quickly let him pop his head out so he can breath properly, a bit like a baby and quickly take him to the other room and let him go again, the towel should stop him from jumping out and escaping.
Just a little disclaimer, make sure you do this very carefully and gently with a breathable fabric and make sure your not trapping him so he’s suffocated in any way, make sure it’s done as quick as possible to save stressing him, also this should only be used as a very occasional tactic when it’s absolutely necessary.
This is a technique I was taught on a college animal management course and has been used for years, often as a technique to catch injured wild animals that don’t want human contact.
Good luck with moving your little bun