Joints are Stretching [Configurable Joints]

Hello,
how can I fix this stretching problem Screenshot - 73006fdd2a5457fea68d2188d8f4a983 - Gyazo

After hitting an object, it freaks out for 0.5 seconds and will stretch.

This are my settings:

Rigidbody:

Configurable Joint:

Physic Settings:

Still need help here :frowning: