I know that accidentally selecting another key item for the Pokéradar would break the chain, but does it apply for chain fishing?? I know there has a been a question for what would break chain fishing, but it didn't include whether other key items has an effect or not, so please help!
I don't want to lose my streak :(
It can break if you use bike or roller skates.
It will not break if you use any other key item.
Going into the bag or using a Key Item such as the Vs.Recorder does not break your chain. If you really wanna know, I used to chain fish the life out of the game xD
Hope this helped!
-It's a secret!