Investment to bidirectional Flow fails

[p-snft]

Describe the bug

Investment to bidirectional Flow leads to an infeasibility.

To Reproduce

See script at https://gist.github.com/p-snft/6106ec8727c78928d2b541afe5ef7501

Expected behavior

Capacity should be optimised (to set minimum) if investment problem is set.

Additional context

I suggested to do it like this to a colleague of mine without testing if it really works, because I was sure it would do. It does not.