Why does my Pokeradar chain keep breaking while I'm running back and forth in the grass?

I’ve been chaining Eevee in Trophy Garden, and twice now, my chain just randomly broke. What happens is I do a battle, catch the Eevee, the chain continues and patches generate, and when I run around in the grass to charge my Poke Radar to get more desirable patches, the chain just randomly breaks.

Is there a reason this happens? I didn’t close my DS or anything, so this is really annoying.

Pleaselog inorregisterto add a comment.

With some help, I figured it out.

A chain can also automatically break if the player uses the Bicycle or Roller Skates,if the player scrolls all shaking grass patches off-screen by moving too far away from them, a Pokémon evolves, or an Egg hatches.

Source

I didn’t get on my bike, evolve a Pokemon, or hatch an egg, and the random chance of your chain breaking is different, because that happens when you enter the shaking grass, whereas this happened while I already had a chain going and didn’t step into the grass. So the only explanation is that I moved too far from the patches, causing the chain to break.