Hello,
I don’t think this is a bug, but certainly an aspect that is not very clear with the system of inputs.
Setting a default value in the input-box editor as you did allows to use this value when the patch is evaluated “from inside” : patches are “closed” objects that are generally not aware of their context (no access to what is entered or connected to the input of the patch box).
This value has no effect outside, at the level of the patch box, where you need to set a value to the input of the box.
This value (even if it is the NIL value) will substitute the default value of the input-box.
I don’t think this is a “new” thing, I believe it always worked like this.
It actually makes sense especially when you are dealing with “blue” (global) abstractions, where a same patch (and therefore, a same input) can be used at several places in other patches, with different input or connected values.
I hope this helps,
Jean