Welcome to the forum!
I’m not familiar with the Ranger at all. Probably not made in the USA.
I don’t think any ever have been?
there’s been some discussion here about airflow.
It’s not a matter of the reeds softening.
I think what you are experiencing is that the air chamber in your melodica is probably large and it takes time to fill it up before the reeds will sound. when you play chords it lets more air escape.
Some brands of melodica have a smaller air chamber and will sound faster and be easier to play chords on.
You really won’t be able to have a melody note stand out the way you may be used to on the guitar.
The air in a melodica hits all the reeds at the same time.