This should be fixed now. Turns out the problem wasn’t with spring constraints, it was with how I solve Rod Constraints (used in rigidbodies)! When you pulled the RigidBody far off, the actual structure made with rod constraints would stretch so far that a large force would be applied to it resulting in its points’ positions to be NaN, subsequently causing the spring constraint to break too.
Upgraded the wally package to v0.3.7. You can replace the old roblox model with the new one!
If you encounter this again, lmk!