There are many different techniques for breaking in a glove. Dozens of conditioners and oils are available.
Leather is tanned all over the world and no two skins or tanners are quite alike.
So your glove may react differently, to different break-in techniques. A glove that is troublesome in breaking in, could be a good quality glove. Long lasting gloves take time to break in. It is best to slowly break in your glove by just using it and keeping it clean and oiled conditioned occasionally. You begin by soaking your glove in a bucket of water, not long, maybe 2 to 3 minutes, then let dry by hanging it in a cool dry place, so as not to form mold, for a week or until it is completely dry.