It leads to a weird situation when different closures attach two different subscribers with the same name. In this case, the second attached subscriber replaces the first one leading to unsubscribing in the first closure.
Just remove the check if the subscriber is named function or store subscribers as function instances.
Possible workaround until the bug is fixed
Pass anonymous subscribers to the .subscribe method like
nb.subscribe(() => update()) // not nb.subscribe(update)
The point is that two different components create two subscriptions to the same Nexus instance. As soon as Form is mounted its subscription replaces the earlier subscription created by List because both components use subscriber functions with the same nameupdate! As a result, the List is never updated anymore.
So storing subscriptions using function names basically is not a good idea.